RENR5978-03
March 2004
Systems Operation
Testing and Adjusting
G3500C and G3500E Engines
RWA1-Up (Engine)
GDB1-Up (Engine)
GHC1-Up (Engine)
GHE1-Up (Engine)
GHM1-Up (Engine)
GHP1-Up (Engine)
DKR1-Up (Engine)
GHR1-Up (Engine)
i01658146
Important Safety Information
Most accidents that involve product operation, maintenance and repair are caused by failure to observe
basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous
situations before an accident occurs. A person must be alert to potential hazards. This person should also
have the necessary training, skills and tools to perform these functions properly.
Improper operation, lubrication, maintenance or repair of this product can be dangerous and
could result in injury or death.
Do not operate or perform any lubrication, maintenance or repair on this product, until you have
read and understood the operation, lubrication, maintenance and repair information.
Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings
are not heeded, bodily injury or death could occur to you or to other persons.
The hazards are identified by the “Safety Alert Symbol” and followed by a “Signal Word” such as
“DANGER”, “WARNING” or “CAUTION”. The Safety Alert “WARNING” label is shown below.
The meaning of this safety alert symbol is as follows:
Attention! Become Alert! Your Safety is Involved.
The message that appears under the warning explains the hazard and can be either written or pictorially
presented.
Operations that may cause product damage are identified by “NOTICE” labels on the product and in
this publication.
Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.
The warnings in this publication and on the product are, therefore, not all inclusive. If a tool,
procedure, work method or operating technique that is not specifically recommended by Caterpillar
is used, you must satisfy yourself that it is safe for you and for others. You should also ensure that
the product will not be damaged or be made unsafe by the operation, lubrication, maintenance or
repair procedures that you choose.
The information, specifications, and illustrations in this publication are on the basis of information that
was available at the time that the publication was written. The specifications, torques, pressures,
measurements, adjustments, illustrations, and other items can change at any time. These changes can
affect the service that is given to the product. Obtain the complete and most current information before you
start any job. Caterpillar dealers have the most current information available.
When replacement parts are required for this
product Caterpillar recommends using Caterpillar replacement parts or parts with equivalent
specifications including, but not limited to, physical dimensions, type, strength and material.
Failure to heed this warning can lead to premature failures, product damage, personal injury or
death.
3
Table of Contents
Table of Contents
Testing and Adjusting Section
Systems Operation Section
Engine Design
Engine Design ....................................................... 4
Engine Design ....................................................... 4
Electronic Control System
Electronic Control System Operation ...................... 5
Electronic Control Module (ECM) .......................... 9
Start/Stop Control ................................................. 10
Engine Governing .................................................. 11
Integrated Temperature Sensing Module .............. 12
Electronic Control System Parameters ................. 13
Engine Sensors .................................................... 19
Electronic Service Tools ........................................ 22
Engine Monitoring System
Engine Monitoring System ................................... 23
Ignition System
Ignition System .................................................... 25
Fuel System
Fuel System Operation ......................................... 27
Air/Fuel Ratio Control ........................................... 30
Air Inlet and Exhaust System
Aftercooler ...........................................................
Compressor Bypass .............................................
Exhaust Manifold .................................................
Turbocharger .......................................................
Valve System Components ...................................
33
34
35
36
36
Lubrication System
Lubrication System .............................................. 38
Cooling System
Cooling System .................................................... 40
Basic Engine
Cylinder Block, Liners and Heads .........................
Pistons, Rings and Connecting Rods ..................
Crankshaft ...........................................................
Camshaft .............................................................
43
45
45
46
Air Starting System
Air Starting System .............................................. 47
Electrical System
Electric Starting System ........................................
Power Supply ........................................................
Grounding Practices ............................................
Alternator .............................................................
Starting Solenoid ..................................................
Starting Motor ......................................................
Circuit Breaker .....................................................
49
51
51
52
53
53
54
Electronic Control System
General Information (Electronic Control System) ..
Engine Governing - Adjust ....................................
Manifold Air Pressure Sensor ...............................
Detonation Sensor ................................................
Engine Speed/Timing Sensor ...............................
Ignition Transformer ..............................................
Fuel System
General Information (Fuel System) .......................
Air/Fuel Ratio Control - Adjust ..............................
Finding the Top Center Position for the No. 1
Piston ..................................................................
Camshaft Timing ...................................................
56
58
59
60
60
61
64
64
65
66
Air Inlet and Exhaust System
Restriction of Air Inlet and Exhaust .......................
Measuring Inlet Manifold Temperature .................
Measuring Exhaust Temperature ..........................
Compression .........................................................
Valve Lash and Valve Bridge Adjustment .............
Crankshaft Position for Valve Lash Setting ...........
70
71
71
72
72
75
Lubrication System
General Information (Lubrication System) ............
Excessive Bearing Wear - Inspect ........................
Excessive Engine Oil Consumption - Inspect .......
Increased Engine Oil Temperature - Inspect ........
Measuring Engine Oil Pressure ............................
76
76
76
77
77
Cooling System
General Information (Cooling System) .................
Visual Inspection ...................................................
Test Tools for the Cooling System ........................
Testing the Cooling System ..................................
78
78
79
80
Basic Engine
Cylinder Block .......................................................
Cylinder Liner Projection .......................................
Flywheel - Inspect .................................................
Flywheel Housing - Inspect ...................................
Vibration Damper - Check ....................................
85
85
86
87
89
Air/Electric Starting System
General Information (Air/Electric Starting
System) ............................................................... 90
Electrical System
Test Tools for the Electrical System ...................... 92
Battery .................................................................. 93
Index Section
Index ..................................................................... 94
4
Systems Operation Section
Systems Operation Section
211-3218 Piston ...................................... 11.3:1
240-5330 Piston ..................................... 13.1:1
..................................................................................
Engine Design
Valve lash setting
i02075246
Engine Design
Inlet ......................................... 0.51 mm (0.020 inch)
Exhaust ................................... 1.27 mm (0.050 inch)
SMCS Code: 1000
Note: The front end of the engine is opposite the
flywheel end of the engine. The left and the right side
of the engine are seen from the flywheel end. The
number 1 cylinder is the front cylinder on the right
side. The number 2 cylinder is the front cylinder on
the left side.
S/N: TJB1-Up; RWA1-Up
S/N: SLY1-Up; GHP1-Up
S/N: TJC1-Up; DKR1-Up
i02075236
Engine Design
SMCS Code: 1000
S/N: CWY1-Up; GDB1-Up
S/N: B9P1-Up; GHC1-Up
S/N: CWW1-Up; GHE1-Up
S/N: SXY1-Up; GHM1-Up
Illustration 1
g01053672
S/N: HAL1-Up; GHR1-Up
Cylinder and valve location
(A) Inlet valve
(B) Exhaust valve
Number and arrangement of
cylinders ............................................ 60 degree V-16
Valves per cylinder .................................................. 4
Displacement ................................. 69 L (4210 cu in)
Bore ............................................. 170 mm (6.7 inch)
Stroke .......................................... 190 mm (7.5 inch)
Illustration 2
Combustion .......................................... Spark ignited
When the crankshaft is viewed from the flywheel
end, the crankshaft rotates in the following
direction. ....................................... Counterclockwise
Firing order
Standard rotation
CCW .. 1, 2, 5, 6, 3, 4, 9, 10, 15, 16, 11, 12, 13, 14, 7, 8
Compression ratio
g01061709
Cylinder and valve location
(A) Inlet valve
(B) Exhaust valve
Number and arrangement of
cylinders ............................................ 60 degree V-20
Valves per cylinder .................................................. 4
Displacement ................................. 86 L (5263 cu in)
Bore ............................................. 170 mm (6.7 inch)
5
Systems Operation Section
Stroke .......................................... 190 mm (7.5 inch)
Combustion .......................................... Spark ignited
When the crankshaft is viewed from the flywheel
end, the crankshaft rotates in the following
direction. ....................................... Counterclockwise
Firing order
Standard rotation CCW ... 1, 2, 11, 12, 3, 4, 15, 16, 7,
8, 19, 20, 9, 10, 17, 18, 5, 6, 13, 14
Compression ratio
211-3218 Piston ...................................... 11.3:1
240-5330 Piston ..................................... 13.1:1
Valve lash setting
Inlet ......................................... 0.51 mm (0.020 inch)
Exhaust ................................... 1.27 mm (0.050 inch)
Note: The front end of the engine is opposite the
flywheel end of the engine. The left and the right side
of the engine are seen from the flywheel end. The
number 1 cylinder is the front cylinder on the right
side. The number 2 cylinder is the front cylinder on
the left side.
Electronic Control System
i02086352
Electronic Control System
Operation
SMCS Code: 1900
G3516
There is one Electronic Control Module (ECM) on
the G3516 Engine.
The ECM controls most of the functions of the engine.
The operator’s interface with the engine control is
provided by the Caterpillar Electronic Technician
(Cat ET) and by the control panel. For information
on Cat ET, refer to Systems Operation/Testing and
Adjusting, “Electronic Service Tools”.
Many of the engine control’s parameters can be
programmed for the specific site. For information
on the programmable parameters, refer to Systems
Operation/Testing and Adjusting, “Electronic Control
System Parameters”.
The starting motor solenoid, the Gas Shutoff Valve
(GSOV), and other components are used to control
start-up and shutdown. For information on start/stop
sequencing, refer to Systems Operation/Testing and
Adjusting, “Start/Stop Control”.
The ECM provides the timing and the voltage for
ignition on the engine. For information on ignition
control, refer to Systems Operation/Testing and
Adjusting, “Ignition System”.
Feedback from sensors and adjustment of the
fuel metering valve enable control of the exhaust
emissions. For information on air/fuel ratio control,
refer to Systems Operation/Testing and Adjusting,
“Air/Fuel Ratio Control”.
The desired speed is maintained through control of
the throttle actuator. For information on governing of
the engine, refer to Systems Operation/Testing and
Adjusting, “Engine Speed Governing”.
A wattmeter or “Generator Output Power Sensor”
provides a signal that represents the generated
ekW to the control system. The generated power
is monitored by the master ECM for two purposes:
control of the air/fuel ratio and operation of the
compressor bypass valve. For information on
the compressor bypass valve, refer to Systems
Operation/Testing and Adjusting, “Compressor
Bypass”.
Other sensors enable the ECM to monitor the engine
operation. For information on engine monitoring and
protection, refer to Systems Operation/Testing and
Adjusting, “Engine Monitoring System”.
The monitoring system includes the Integrated
Temperature Sensing Module (ITSM). The ITSM
monitors the engine’s exhaust temperatures.
For information on the module, refer to Systems
Operation/Testing and Adjusting, “Integrated
Temperatutre Sensing Module (ITSM)”.
Illustration 3 is a diagram of the components in the
engine’s electronic control system.
6
Systems Operation Section
Illustration 3
g01061981
7
Systems Operation Section
G3520
There are two electronic control modules on the
G3520 Engine, the master Electronic Control Module
(ECM) and the slave ECM.
The master ECM controls most of the functions
of the engine. The operator’s interface with the
engine control is provided by the Caterpillar
Electronic Technician (Cat ET) and by the control
panel. For information on Cat ET, refer to Systems
Operation/Testing and Adjusting, “Electronic Service
Tools”.
Many of the engine control’s parameters can be
programmed for the specific site. For information
on the programmable parameters, refer to Systems
Operation/Testing and Adjusting, “Electronic Control
System Parameters”.
The starting motor solenoid, the Gas Shutoff Valve
(GSOV), and other components are used to control
start-up and shutdown. For information on start/stop
sequencing, refer to Systems Operation/Testing and
Adjusting, “Start/Stop Control”.
The master ECM provides the timing and the voltage
for ignition on the engine’s left bank. The slave
ECM controls the ignition on the right bank. For
information on ignition control, refer to Systems
Operation/Testing and Adjusting, “Ignition System”.
Feedback from sensors and adjustment of the
fuel metering valve enable control of the exhaust
emissions. For information on air/fuel ratio control,
refer to Systems Operation/Testing and Adjusting,
“Air/Fuel Ratio Control”.
The desired speed is maintained through control of
the throttle actuator. For information on governing of
the engine, refer to Systems Operation/Testing and
Adjusting, “Engine Speed Governing”.
A wattmeter or “Generator Output Power Sensor”
provides a signal that represents the generated
ekW to the control system. The generated power
is monitored by the master ECM for two purposes:
control of the air/fuel ratio and operation of the
compressor bypass valve. For information on
the compressor bypass valve, refer to Systems
Operation/Testing and Adjusting, “Compressor
Bypass”.
Other sensors enable the master ECM and the
slave ECM to monitor the engine operation. For
information on engine monitoring and protection,
refer to Systems Operation/Testing and Adjusting,
“Engine Monitoring System”.
The monitoring system includes the Integrated
Temperature Sensing Module (ITSM). The ITSM
monitors the engine’s exhaust temperatures.
For information on the module, refer to Systems
Operation/Testing and Adjusting, “Integrated
Temperatutre Sensing Module (ITSM)”.
Illustration 4 is a diagram of the components in the
engine’s electronic control system.
8
Systems Operation Section
Illustration 4
g01011524
9
Systems Operation Section
i02086642
G3520
Electronic Control Module
(ECM)
SMCS Code: 1901
G3516
Illustration 6
g01011596
There are two electronic control modules on the G3520B engine.
(1) Master ECM
(2) Slave ECM
Illustration 5
g01063688
There is one electronic control module on the G3516 engine.
(1) ECM
The ECM (1) controls the engine’s functions. The
module is an environmentally sealed unit that is in
an engine mounted terminal box. The ECM monitors
various inputs from sensors in order to activate
relays, solenoids, etc at the appropriate levels. The
ECM supports the following primary functions:
The master ECM (1) controls most of the engine’s
functions. The module is an environmentally sealed
unit that is in an engine mounted terminal box. The
ECM monitors various inputs from sensors in order
to activate relays, solenoids, etc at the appropriate
levels. The ECM supports the following primary
functions:
• Start/stop control
• Control of ignition for the left bank
• Governing of the engine
• Start/stop control
• Air/fuel ratio control
• Control of ignition
• Monitoring of the detonation sensors on the left
• Governing of the engine
• Air/fuel ratio control
• Monitoring of the detonation sensors
• Monitoring of the electrical system
• Monitoring of engine operation
The ECM does not have a removable personality
module. The software is changed by the flash
programming of a file via the Caterpillar Electronic
Technician (Cat ET).
bank
• Monitoring of the electrical system
• Monitoring of engine operation
The slave ECM (2) supports the following functions:
• Control of ignition for the right bank
• Monitoring of the detonation sensors on the right
bank
Neither ECM has a removable personality module.
The software is changed by the flash programming
of a file via the Caterpillar Electronic Technician (Cat
ET).
10
Systems Operation Section
i02084137
Start/Stop Control
SMCS Code: 1416; 4462
The ECM contains the logic and the outputs for
control of starting and of shutdown. The customer
programmable logic responds to signals from
the following components: engine control switch,
emergency stop switch, remote start switch, data
link, and other inputs.
The following Steps describe the electronic control
system’s start/stop sequencing:
1. The ECM receives one of the following signals
for start-up:
5. After the engine starts and the programmable
crank terminate speed is achieved, the ECM
removes the voltage from the starting motor’s
solenoid. The starter motor pinion disengages
from the flywheel ring gear.
6. The engine runs until the ECM receives a
shutdown signal.
The following conditions cause a shutdown signal:
• The remote start/stop initiate contact opens
when the engine control switch is in the “AUTO”
position.
• The engine control switch is turned to the
“STOP” position or to the “OFF/RESET”
position.
• The engine control is set to the “START” mode.
• The “EMERGENCY STOP” button is pressed.
• The engine control is in the “AUTO” mode and
• The ECM senses an undesirable operating
the remote start/stop initiate contact closes.
2. After receiving a signal for start-up, the ECM waits
for the programmable “Driven Equipment Delay
Time” prior to cranking.
The ECM will not start the engine until the input
for driven equipment is grounded.
If the driven equipment’s input circuit is opened
during engine operation, the engine will shut down.
3. After input for the driven equipment is grounded,
the ECM supplies +Battery voltage to the solenoid
for the starting motor. The starting motor cranks
the engine without fuel and without ignition until
the “Engine Purge Cycle Time” has elapsed.
The “Engine Purge Cycle Time” allows any
unburned fuel to exit through the exhaust system
prior to ignition. This helps prevent combustion
in the exhaust system.
4. After the “Engine Purge Cycle Time” has elapsed,
the Gas Shutoff Valve (GSOV) is energized. The
GSOV may be energized by the ECM, or by the
customer’s equipment. The ECM energizes the
ignition transformers. The ECM sends a fuel
command to the fuel metering valve in order to
supply sufficient fuel for a combustible air/fuel
mixture. The ECM also sends a throttle command
to the throttle actuator.
The engine has an energize-to-run type of GSOV.
This means that the GSOV must be energized in
order to open. When the GSOV is open, fuel is
allowed to flow to the engine.
condition and an engine shutdown is initiated.
The engine control switch’s “OFF/RESET” position
is not recommended for normal shutdown. The
“EMERGENCY STOP” is not recommended for
normal shutdown. Any shutdown that is initiated
by the ECM is not a normal shutdown. Any of
these types of shutdowns cause the fuel and the
ignition to be stopped immediately. The cool down
cycle cannot operate.
Any shutdown that is initiated by the ECM is the
result of a condition that is undesirable and/or
unplanned.
One of the following conditions initiates a normal
shutdown:
• The engine control switch is turned to the
“STOP” position.
• The engine control switch is in the “AUTO”
position and the remote start/stop initiate
contact opens.
7. The engine operates for the programmable cool
down period before the engine stops. After the
cool down period, the ECM removes the +Battery
voltage from the solenoid for the GSOV and the
fuel flow is stopped.
8. The ignition continues to operate without a fuel
supply until the engine speed is less than 40 rpm.
Then, the ECM terminates the ignition. The engine
coasts to a stop.
11
Systems Operation Section
If the engine speed is not reduced by at least 100
rpm during the programmable “Engine Speed
Drop Time”, the ECM terminates the ignition. The
ECM activates an emergency stop.
i01961691
Engine Governing
SMCS Code: 1901
Illustration 7
g01011687
Diagram of the governing system
The Electronic Control Module (ECM) continuously
strives to achieve the engine speed that is desired for
the operating condition.
• If the engine oil pressure is less than the setpoint
The desired engine speed is determined by these
factors:
• If the engine oil pressure is greater than the
Desired Speed Input – A signal of either 0 to 5 VDC
or 4 to 20 mA can provide this input. The “Desired
Speed Input Configuration” determines the input that
is used by the ECM. This input can be provided by a
potentiometer.
Programmable Parameters – The Caterpillar
Electronic Technician (Cat ET) is used to program
these parameters that affect the desired engine
speed: “Low Idle Speed”, “Minimum High Idle
Speed”, and “Maximum High Idle Speed”. The
programmable “Engine Accel. Rate” determines
the rate of acceleration and of deceleration. The
“Governor Type Setting” parameter can be set
to “Droop” or to “Isochronous”. Refer to Systems
Operation/Testing and Adjusting, “Electronic Control
System Parameters” for additional information on
these parameters.
Idle/Rated Switch – The idle/rated switch is optional.
If the idle/rated switch is used, the engine speed can
also be affected by the engine oil pressure:
• If the idle/rated switch is in the idle position, the
ECM will always select the low idle speed.
for the low pressure warning, the ECM will always
select the low idle speed.
setpoint for the low pressure warning and the
idle/rated switch is in the rated position, the ECM
will select the rated speed.
The actual engine speed is detected via a signal from
the engine speed/timing sensor. The ECM compares
the actual engine speed to the desired engine speed.
The ECM functions as an electronic governor in order
to develop a throttle command.
The electronic governor uses gains in order to provide
stable operation. Two sets of gains are available. The
ECM uses the value of the “Grid Status” parameter in
order to determine the set of gains that is used. If the
“Grid Status” is OFF, the ECM uses the gains for the
primary governor. If the “Grid Status” is ON, the ECM
uses the gains for the auxiliary governor.
The governor’s throttle command is a percent of the
maximum position of the throttle. The value of the
throttle command can be viewed on Cat ET. The
throttle command is sent to the throttle actuator. The
throttle actuator is mechanically connected to the
throttle body. There is no feedback for the throttle
position.
12
Systems Operation Section
i01943970
Integrated Temperature
Sensing Module
SMCS Code: 1901
g01011776
Illustration 8
(1) Integrated Temperature Sensing Module (ITSM)
g01011777
Illustration 9
(2) Thermocouple for a cylinder’s exhaust
port
(3) Thermocouple for the temperature of an
exhaust inlet to a turbocharger turbine
(4) Thermocouples for the temperature of
the turbocharger’s exhaust
(5) Thermocouple for the temperature of the
turbocharger’s exhaust
13
Systems Operation Section
The Integrated Temperature Sensing Module (ITSM)
monitors thermocouples that measure the engine’s
exhaust temperatures. The ITSM calculates the
average exhaust temperature for each bank. The
temperatures are broadcast over the CAT data link
for use with other modules.
Table 1
Configuration Parameters for G3500C and
G3500E Engines
Timing Control
“First Desired Timing”
Thermocouples measure the exhaust temperatures
from the exhaust port of each cylinder. To observe
the value of the output of the thermocouples, use Cat
ET to view the “Cylinder #X Exhaust Port”. The “X” is
the number for the particular cylinder.
“Second Desired Timing”
A thermocouple is mounted at the inlet for the
exhaust gas of each turbocharger turbine. To observe
the value of the output of the thermocouples, use Cat
ET to view the “Left Bank Turbine Inlet Temp” or the
“Right Bank Turbine Inlet Temp”.
“Fuel Specific Heat Ratio”
A thermocouple is mounted at the outlet for the
exhaust gas of each turbocharger turbine. To observe
the value of the output of the thermocouples, use Cat
ET to view the “Left Bank Turbine Outlet Temp” or the
“Right Bank Turbine Outlet Temp”.
The following conditions can activate an alarm or a
shutdown. The trip points can be programmed with
Cat ET.
• The temperature is higher than the limit that is
programmed.
• The temperature is lower than the limit that is
programmed.
• The temperature of a cylinder deviates significantly
from the average temperature for all of the
cylinders.
Air/Fuel Ratio Control
“Fuel Quality”
“Gas Specific Gravity”
“Desired Emission Gain Adjustment”
“Air/Fuel Proportional Gain”
“Air/Fuel Integral Gain”
Speed Control
“Low Idle Speed”
“Minimum High Idle Speed”
“Maximum High Idle Speed”
“Engine Accel. Rate”
“Desired Speed Input Configuration”
“Governor Type Setting”
“Engine Speed Droop”
“Governor Proportional Gain”
“Governor Integral Gain”
“Governor Derivative Gain”
“Auxiliary Proportional Governor Gain 1”
“Auxiliary Integral Governor Gain 1”
“Auxiliary Derivative Governor Gain 1”
i02075333
Start/Stop Control
Electronic Control System
Parameters
“Driven Equipment Delay Time”
SMCS Code: 1901
“Engine Purge Cycle Time”
Configuration Parameters
Certain parameters are unique for each engine
application. Table 1 is a list of the parameters that can
be configured for G3500C and G3500E Engines. The
parameters are described below. The parameters
are programmed into the Electronic Control Module
(ECM) via the Caterpillar Electronic Technician (Cat
ET). The values of the parameters can be viewed on
the “Configuration” screen of Cat ET.
“Crank Terminate Speed”
“Engine Cooldown Duration”
“Cycle Crank Time”
“Engine Overcrank Time”
“Engine Speed Drop Time”
“Engine Pre-lube Time Out Period”
Monitoring and Protection
“High Inlet Air Temp Load Set Point”
Power Monitoring
“Generator Output Power Sensor Scale Factor”
“Generator Output Power Sensor Offset”
(continued)
14
Systems Operation Section
Air/Fuel Ratio Control
(Table 1, contd)
Configuration Parameters for G3500C and
G3500E Engines
“Engine Output Power Configuration”
“Engine Driven Accessory Load Configuration”
Information for the ECM
“Engine Serial Number”
“Equipment ID”
“Customer Password #1”
“Customer Password #2”
“Total Tattletale”
Timing Control
The “Desired Timing” parameters allow the customer
to electronically program the timing of the ignition
spark of the electronic system in order to meet
the needs for specific applications and specific
installations. The desired timing value can be
changed while the engine is running or while the
engine is stopped. The value that is entered for the
desired timing is the ignition timing when the engine
is operating at rated speed and at full load.
Note: The actual ignition timing at a given instance
may vary from the desired timing value. This variance
is due to variations in the engine speed or the
detonation.
The range for programming the desired timing is 0 to
40 degrees before the top center (TC) position.
“First Desired Timing”
The “First Desired Timing” is determined with the
methane number of the primary fuel that is used. Use
the Engine Performance Sheet, “Fuel Usage Guide”.
The ECM selects the “First Desired Timing” when the
switch for the selection of the timing is in the open
position.
“Second Desired Timing”
The “Second Desired Timing” is determined with the
methane number of the alternate fuel that is used and
the Engine Performance Sheet, “Fuel Usage Guide”.
The ECM selects the “Second Desired Timing” when
the timing selection switch is in the closed position. If
an alternate fuel is not used, enter the same timing
that was entered in the “First Desired Timing”.
Before the initial start-up, a current gas analysis
is required. Periodic gas analyses are also
recommended. Data from the gas analysis must
be entered into Caterpillar Software, LEKQ6378,
“Methane Number Program”. The results are
programmed into the ECM.
Note: It is very important to use the Caterpillar
Software, LEKQ6378, “Methane Number
Program”. Use of only the data from the gas analysis
can result in incorrect settings.
“Fuel Quality”
This is the fuel’s Low Heat Value (LHV). The air/fuel
ratio control of the ECM will compensate for some
inaccuracy in this setting. The ECM assumes
a corrected value that is multiplied by the “Fuel
Correction Factor”. This factor can be displayed on
the Cat ET screen.
The “Fuel Quality” parameter can be used to change
the air/fuel ratio when the engine is operating in
the open loop mode. To richen the air/fuel mixture,
reduce the value. The calculation will compensate
for the reduced LHV by increasing the fuel flow. To
lean the air/fuel mixture, increase the value. The
calculation will compensate for the increased LHV
by reducing the fuel flow.
“Gas Specific Gravity”
This is the fuel’s specific gravity in relation to the
specific gravity of air. The ECM does not use this
information. The ECM provides the information to the
fuel metering valve via the CAN data link. The fuel
metering valve requires an input for the “Gas Specific
Gravity” in order to precisely meter the fuel flow.
“Fuel Specific Heat Ratio”
This is a ratio of the fuel’s specific heat at a constant
pressure and at a constant volume. The ratio is also
known as “k”. The ratio is related to the expansion
of the gas across the fuel metering valve. The ECM
does not use this information. The ECM provides the
information to the fuel metering valve via the CAN
data link. The fuel metering valve requires an input
for the “Fuel Specific Heat Ratio” in order to precisely
meter the fuel flow.
Enter a value of 1.4 for processed, dry pipeline
natural gas.
15
Systems Operation Section
“Desired Emission Gain Adjustment”
This is an adjustment for the level of the engine’s
exhaust emissions for engine operation at full load.
The adjustable range is 85 to 115.
Refer to Testing and Adjusting, “Air/Fuel Ratio
Control - Adjust”.
“Air/Fuel Proportional Gain”
The “Air/Fuel Proportional Gain” determines the
speed of the fuel metering valve’s response in
adjusting for the difference between the actual air/fuel
ratio and the desired air/fuel ratio.
The factory default setting is 0. This value should
not require adjustment. If problems occur, this is
one of the last parameters that should be adjusted.
The adjustable range is −50 to +50. Negative
values reduce the speed of the fuel metering valve’s
response and positive values increase the speed of
the fuel metering valve’s response.
“Air/Fuel Integral Gain”
The “Air/Fuel Integral Gain” determines the response
of the fuel metering valve to the error that is
accumulated over time for the air/fuel ratio.
The factory default setting is 0. This value should
not require adjustment. If problems occur, this is
one of the last parameters that should be adjusted.
The adjustable range is −50 to +50. Negative values
reduce the response of the valve and positive values
increase the response of the valve.
For the 1200 rpm arrangement, the minimum high
idle speed can be programmed between 800 rpm
and 1200 rpm. The default value is 1200 rpm.
The “Minimum High Idle Speed” and the “Maximum
High Idle Speed” determine the slope of the desired
speed input.
“Maximum High Idle Speed”
Program this parameter to the desired maximum high
idle rpm. The actual high idle speed is regulated by
the desired speed input. The regulation is linear in
proportion to the input. An input of 0 percent results
in the minimum high idle rpm and an input of 100
percent results in the maximum high idle rpm.
For the 50 Hz arrangement, the maximum high idle
speed can be programmed between 1500 rpm and
1900 rpm. The default value is 1600 rpm.
For the 60 Hz arrangement, the maximum high idle
speed can be programmed between 1800 rpm and
2200 rpm. The default value is 2000 rpm.
For the 1200 rpm arrangement, the maximum high
idle speed can be programmed between 1200 rpm
and 1600 rpm. The default value is 1400 rpm.
“Engine Accel. Rate”
This parameter controls the rate for engine response
to a change in the desired engine speed. For
example, the engine can be programmed to
accelerate at a rate of 50 rpm per second when the
“Idle/Rated” switch is turned to the “Rated” position.
Speed Control
“Desired Speed Input Configuration”
“Low Idle Speed”
This parameter determines the signal input to the
ECM for control of the desired speed. The signal can
be either 0 to 5 VDC or 4 to 20 mA.
Program this parameter to the desired low idle rpm.
The low idle rpm can be programmed within the
range of 500 to 1100 rpm.
“Minimum High Idle Speed”
Program this parameter to the desired minimum high
idle rpm. The actual high idle speed is regulated by
the desired speed input. The regulation is linear in
proportion to the input. An input of 0 percent results
in the minimum high idle rpm and an input of 100
percent results in the maximum high idle rpm.
For the 50 Hz arrangement, the minimum high idle
speed can be programmed between 900 rpm and
1500 rpm. The default value is 1400 rpm.
For the 60 Hz arrangement, the minimum high idle
speed can be programmed between 900 rpm and
1800 rpm. The default value is 1600 rpm.
Note: The ECM is not configured to accept a pulse
width modulated signal for input of the desired engine
speed. If you try to select a Pulse Width Modulated
input (PWM), the ECM will reject the selection. An
error will be generated.
“Governor Type Setting”
The “Governor Type Setting” parameter can be set
to “Droop Operation” or to “Isochronous Mode”. This
setting is dependent upon the application of the
engine.
“Engine Speed Droop”
This programmable parameter allows precise control
of the speed droop. The “Governor Type Setting”
parameter must be set to “Droop”. The droop can be
programmed to a value between 0 and 10 percent.
16
Systems Operation Section
Governor Gain Settings
Refer to Testing and Adjusting, “Engine Governing Adjust” for the adjustment procedure for the governor.
“Governor Proportional Gain”
This parameter changes the reaction of the throttle
actuator when the “Grid Status” parameter is “On”. If
this value is changed and the “Grid Status” is “Off”,
the stability of the engine will not change. If changing
this value causes no effect, check the “Grid Status” in
order to make sure that the status is “On”.
This parameter is based on a proportional multiplier.
The “Governor Proportional Gain” determines the
speed of the throttle actuator’s response in adjusting
for the difference between the actual speed and the
desired speed. Increasing this value provides a faster
response to the difference between the actual speed
and the desired speed.
“Auxiliary Integral Governor Gain 1”
This parameter changes the reaction of the throttle
actuator when the “Grid Status” parameter is “Off”. If
changing this value causes no effect, check the “Grid
Status” in order to make sure that the status is “Off”.
This parameter changes the reaction of the throttle
actuator when the “Grid Status” parameter is “On”. If
this value is changed and the “Grid Status” is “Off”,
the stability of the engine will not change. If changing
this value causes no effect, check the “Grid Status” in
order to make sure that the status is “On”.
“Governor Integral Gain”
This parameter is based on an integral multiplier.
The “Governor Integral Gain” controls the speed for
elimination of the error in the difference between the
actual speed and the desired speed. Increasing this
value provides less damping.
This parameter changes the reaction of the throttle
actuator when the “Grid Status” parameter is “Off”. If
changing this value causes no effect, check the “Grid
Status” in order to make sure that the status is “Off”.
“Governor Derivative Gain”
This parameter is based on a derivative multiplier.
The “Governor Derivative Gain” is used to adjust for
the time delay between the control signal and the
movement of the throttle actuator. If this value is too
low, the engine speed will slowly hunt. If this value is
too high, the engine speed will rapidly fluctuate.
This parameter changes the reaction of the throttle
actuator when the “Grid Status” parameter is “Off”. If
changing this value causes no effect, check the “Grid
Status” in order to make sure that the status is “Off”.
“Auxiliary Proportional Governor Gain 1”
This parameter is based on a proportional multiplier.
The “Auxiliary Proportional Governor Gain 1”
determines the speed of the throttle actuator’s
response in adjusting for the difference between the
actual speed and the desired speed. Increasing this
value provides a faster response to the difference
between the actual speed and the desired speed.
This parameter is based on an integral multiplier.
The “Auxiliary Integral Governor Gain 1” controls the
speed for elimination of the error in the difference
between the actual speed and the desired speed.
Increasing this value provides less damping.
“Auxiliary Derivative Governor Gain 1”
This parameter is based on a derivative multiplier.
The “Auxiliary Derivative Governor Gain 1” is used to
adjust for the time delay between the control signal
and the movement of the throttle actuator. If this
value is too low, the engine speed will slowly hunt. If
this value is too high, the engine speed will rapidly
fluctuate.
This parameter changes the reaction of the throttle
actuator when the “Grid Status” parameter is “On”. If
this value is changed and the “Grid Status” is “Off”,
the stability of the engine will not change. If changing
this value causes no effect, check the “Grid Status” in
order to make sure that the status is “On”.
Start/Stop Control Parameters
“Driven Equipment Delay Time”
The ECM accepts an input from the driven equipment
that indicates when the equipment is ready for
operation. When the input is grounded, the driven
equipment is ready. The ECM will not start the engine
until this input is grounded.
The ECM can be programmed to wait for a certain
period of time after receiving a start command before
starting the engine. This allows the driven equipment
to get ready for operation.
When the ECM receives a start command, the ECM
will wait for the amount of time that is programmed
into the “Driven Equipment Delay Time”. If the “Driven
Equipment Delay Time” elapses and the input is not
grounded, an event code is activated. The engine
will not start.
17
Systems Operation Section
If the “Driven Equipment Delay Time” is programmed
to “0” the delay is disabled. If the ECM receives a
start command and the driven equipment is not ready,
an event code is activated. The engine will not start.
1. The fuel and the ignition are OFF. The engine will
crank for 10 seconds in order to purge gas from
the engine and from the exhaust system.
“Crank Terminate Speed”
2. The fuel and the ignition are enabled. The engine
will continue to crank for a maximum of 30
seconds.
The ECM disengages the starting motor when the
engine speed exceeds the programmed “Crank
Terminate Speed”. The default value of 250 rpm
should be sufficient for all applications.
3. If the engine does not start, the ignition, the fuel,
and the starting motor are disabled for a 30
second “Rest Cycle”.
“Engine Purge Cycle Time”
The “Engine Purge Cycle Time” is the duration
of engine cranking without fuel before the actual
start-up. The ignition is disabled during this time. The
“Engine Purge Cycle Time” allows any unburned fuel
to exit through the exhaust before you run the engine.
“Engine Cooldown Duration”
When the ECM receives a “Stop” request, the engine
will continue to run in the “Cooldown Mode” for
the programmed cooldown period. The “Cooldown
Mode” is exited early if a request for an emergency
stop is received by the ECM. If the “Engine Cooldown
Duration” is programmed to zero, the engine will
immediately shut down when the ECM receives a
“Stop” request.
“Cycle Crank Time”
The “Cycle Crank Time” is the amount of time for
activation of the starting motor and the gas shutoff
valve for start-up. If the engine does not start within
the specified time, the attempt to start is suspended
for a “Rest Cycle” that is equal to the “Cycle Crank
Time”.
“Engine Overcrank Time”
The “Engine Overcrank Time” is the duration for
attempting an engine start-up. An event is generated
if the engine does not start within this period of time.
With this example, a complete cycle is 70 seconds:
a purge cycle of 10 seconds, a cycle crank of 30
seconds, and a rest cycle of 30 seconds. A maximum
of one crank cycle is recommended. The “Overcrank
Time” of 45 seconds allows one crank cycle.
“Engine Speed Drop Time”
This parameter is activated when the ECM receives
the signal for stopping the engine. This input ensures
the shutdown in case the Gas Shutoff Valve (GSOV)
does not close.
If the ECM is controlling the GSOV, the ECM
removes power from the GSOV after the cooldown
period has elapsed. If the customer’s equipment is
controlling the GSOV, the customer’s equipment
removes power from the GSOV after the cooldown
period has elapsed.
In ether cases, the fuel is shut off from the engine.
The ignition continues until the engine speed drops
below 40 rpm. If the engine rpm does not drop at
least 100 rpm within the programmed drop time, the
ECM terminates the ignition and the ECM issues an
emergency stop.
“Engine Pre-Lube Time Out Period”
At the time of this publication, this parameter is not
active.
Monitoring and Protection
“High Inlet Air Temp Engine Load
Setpoint”
Example Setting
Table 2
Examples of the Settings for Start-up
Parameter
Time
“Purge Cycle Time”
10 seconds
“Cycle Crank Time”
30 seconds
“Overcrank Time”
45 seconds
The following sequence will occur if the parameters
are programmed according to the example in Table 2:
The programmable setpoint is a value that separates
low engine load from high engine load for events
that are activated by high inlet air temperature. An
“Engine Load Factor” can be displayed on a Cat
ET status screen. If the load factor is less than
the setpoint and the inlet air temperature reaches
the trip point, a “High Inlet Air Temperature at Low
Engine Load” event is activated. If the load factor is
greater than the setpoint and the inlet air temperature
reaches the trip point, a “High Inlet Air Temperature
at High Engine Load” event is activated.
18
Systems Operation Section
Power Monitoring
The ECM monitors the generator’s output power in
order to accurately control the air/fuel ratio. The ECM
uses an output from one of the following sources in
order to monitor the generator’s output power:
For example, if the generator’s rated output is 1700
ekW, the correct value for the “Generator Output
Power Sensor Scale Factor” parameter is 390. In this
example, the relationship between the voltage level
of the signal and the generator’s output is shown in
Illustration 10 .
• Electronic Modular Control Panel II+ (EMCP II+)
• Programmable Logic Controller (PLC)
• Wattmeter
The PLC and the wattmeter are also called power
sensors.
The ECM uses the values of the “Power Monitoring”
parameters to estimate the generator’s actual power
output. The electronic control module’s estimate of
the generator’s actual power output is displayed on
Cat ET as the “Generator Real kW” parameter in
Status Group 1. If the value of this parameter is within
one percent of the generator’s actual power output,
the ECM will accurately control the air/fuel ratio.
“Generator Output Power Sensor Scale
Factor”
If the generator is equipped with the EMCP II+,
information on the generator’s output is provided
to the ECM via the CAT data link. The value for
the “Generator Output Power Sensor Scale Factor”
parameter is correctly programmed at the factory. No
further adjustment is necessary for this parameter.
If the generator is equipped with a power sensor,
the signal from the power sensor increases from 0
to 4.8 VDC as the generator’s output increases to
the maximum output. The maximum output is 110
percent of the generator’s rated output. For example,
if the generator has a rated output of 1700 ekW, the
maximum output is 1870 ekW. When the generator’s
output is 1870 ekW, the power sensor will provide a
signal of approximately 4.8 VDC.
The ECM requires a scale factor in order to estimate
the generator’s output. The equation that is used to
determine the scale factor is provided in Table 3.
Table 3
Computing the Value for the “Generator Output
Power Sensor Scale Factor”
(R x 1.1) ÷ 4.8
R is the generator’s rated output in kilowatts.
Illustration 10
g01062926
In this example, the value of the “Generator Output Power Sensor
Scale Factor” parameter is 390.
The ECM multiplies the signal voltage by the scale
factor in order to estimate the generator’s output. In
this example, a signal level of 3.5 VDC indicates that
the generator output is approximately 1365 ekW.
After the ECM estimates the generator’s output,
the ECM adds the value of the “Generator Output
Power Sensor Offset” parameter to the estimate. This
refines the electronic control module’s estimate of the
generator’s actual output.
“Generator Output Power Sensor Offset”
If the generator is equipped with the EMCP II+,
information on the generator’s output is provided to
the ECM via the CAT data link. The value for the
“Generator Output Power Sensor Offset” parameter
is correctly programmed at the factory. No further
adjustment is necessary for this parameter.
If the generator is equipped with a power sensor,
the power sensor’s output may not be zero when
the generator’s output is zero. When this occurs,
the power sensor has an offset voltage. The offset
voltage may be positive or negative. In most cases,
the offset voltage is very low. Therefore, the value
of the “Generator Output Power Sensor Offset”
parameter must be set to zero.
The offset voltage must be measured before you
change this parameter from zero. To measure the
offset voltage, refer to Troubleshooting, “Generator
Output Power Readings Do Not Match”. If the offset
voltage is less than 0.01 VDC, the value of the
“Generator Output Power Sensor Offset” must be set
to zero.
19
Systems Operation Section
The value of this parameter is in units of ekW. The
minimum programmable value for this parameter is
−327 ekW. The maximum programmable value for
this parameter is 200 ekW.
The ECM adds the value of the “Generator Output
Power Sensor Offset” parameter to the value that is
determined by the “Generator Output Power Sensor
Scale Factor” parameter. This refines the electronic
control module’s estimate of the generator’s actual
output.
The electronic control module’s final estimate of the
generator’s actual output is displayed on Cat ET as
the “Generator Real kW” parameter in Status Group
1. If the value of this parameter is within one percent
of the generator’s actual power output, the ECM will
accurately control the air/fuel ratio.
“Engine Output Power Configuration”
This parameter applies to all sources.
The value of the “Engine Output Power Configuration”
parameter is the engine’s full load rating in ekW.
The rating is stamped on the engine’s Information
Plate. During operation, the ECM uses this value to
determine the engine’s load as a percentage of the
maximum load.
“Engine Driven Accessory Load
Configuration”
This parameter applies to all sources.
The value of this parameter is the rated load of the
auxiliary equipment such as a radiator fan that is
directly driven by the engine. The value is in units of
ekW. The ECM adds this load to the estimate of the
generator’s actual output in order to determine the
total load on the engine.
Information for the ECM
“Engine Serial Number”
The engine serial number is programmed into the
ECM at the factory. The number is stamped on the
engine Information Plate.
“Equipment ID”
The customer can assign an “Equipment ID” for the
purpose of identification.
Customer Passwords
Two customer passwords can be entered. The
passwords are used to protect certain configuration
parameters from unauthorized changes.
Note: Factory level security passwords are required
for clearing certain logged events and for changing
certain programmable parameters. Because of the
passwords, only authorized personnel can make
changes to some of the programmable items in the
ECM. When the correct passwords are entered, the
changes are programmed into the ECM.
“Total Tattletale”
This item displays the number of changes that have
been made to the configuration parameters.
i01944115
Engine Sensors
SMCS Code: 1559; 1912; 1917
The information from the sensors enables the
Electronic Control Module (ECM) to control the
engine as efficiently as possible over a wide range
of operating conditions.
The sensors also enable the module to activate
alarms, derates, and shutoffs in response to
abnormal operation. The functions of the sensors are
described below.
20
Systems Operation Section
Illustration 11
Right side of the engine
(1) Engine oil temperature sensor
(2) Pressure sensor for unfiltered oil
(3) Pressure sensor for filtered oil
(4) Pressure switch for the coolant pump
(inlet)
Engine oil temperature sensor (1) – An oil
temperature sensor measures the engine oil
temperature. A high oil temperature will activate
an alarm or a shutdown. The trip points can be
programmed with Cat ET. To observe the output
value of the sensor, use Cat ET to view the “Engine
Oil Temperature” parameter.
Oil pressure sensors (2) and (3) – The engine oil
pressure is measured before the oil filters (2) and
after the oil filters (3). An alarm or a shutdown can be
activated by any of the following occurrences: low
filtered oil pressure, low oil filter differential pressure,
and high oil filter differential pressure. The trip point
for the activation of a warning or a shutdown for oil
filter differential pressure can be programmed with
Cat ET. To observe the value of the output of the
sensor, use Cat ET to view the “Engine Oil Pressure”
or the “Unfiltered Engine Oil Pressure” parameter.
Pressure switch for the coolant pump (inlet)
(4) – A pressure switch is located at the inlet for the
engine jacket water. If the inlet pressure is too high,
the switch will activate a shutdown. To observe the
status of the switch, use the Caterpillar Electronic
Technician (Cat ET) to view the “Engine Coolant
Pump Pressure” parameter.
g00928525
21
Systems Operation Section
g00928526
Illustration 12
Top view of the engine
(5) Engine coolant temperature sensor
(6) Manifold air pressure sensor
(7) Engine coolant pressure sensor (outlet)
(8) Manifold air temperature sensor
Engine coolant temperature sensor (5) –
The temperature sensor is located in the water
temperature regulator housing. To monitor the
coolant temperature, the element must be in contact
with the coolant. Otherwise, the sensor will not
function properly. A high coolant temperature will
activate an alarm or a shutdown. A low coolant
temperature will only activate an alarm. The trip
points for the activation can be programmed with Cat
ET. The engine can be restarted after a shutdown
due to high engine coolant temperature. However,
another shutdown will occur after one minute if the
temperature remains high. To observe the value of
the output of the sensor, use Cat ET to view the
“Engine Coolant Temperature” parameter.
Manifold air pressure sensor (6) – The sensor for
inlet manifold air pressure is connected to the air inlet
manifold near the number one cylinder. The sensor
monitors the absolute manifold air pressure. This is
the atmospheric pressure plus the gauge pressure.
The information is used by the ECM to calculate the
airflow. To observe the output value of the sensor,
use Cat ET to view the “Inlet Manifold Air Pressure
(abs)” parameter.
Engine coolant pressure sensor (outlet) (7) – A
pressure switch is located at the outlet for the engine
jacket water. If the outlet pressure is too low, the ECM
will activate a shutdown.
Manifold air temperature sensor (8) – A sensor
for monitoring the inlet manifold air temperature is
located in the inlet elbow for the number twenty
cylinder. Excessive manifold air temperature can
activate an alarm or a shutdown during high load or
low load operation. The trip points for activation can
be programmed with Cat ET. To observe the value of
the output of the sensor, use Cat ET to view the “Inlet
Air Temperature” parameter.
22
Systems Operation Section
i01944195
Electronic Service Tools
SMCS Code: 0785
Caterpillar Electronic Service Tools are designed to
help the service technician perform the following
functions:
• Obtain data.
• Diagnose problems.
• Read parameters.
• Program parameters.
• Calibrate sensors.
The tools that are listed in Table 4 are required in
order to enable a service technician to perform the
functions.
Illustration 13
g00928527
Left side of the engine
(9) Detonation sensor
(10) Speed/timing sensor
Detonation sensors (9) – The detonation sensors
monitor the engine for mechanical engine vibrations.
Each sensor monitors two cylinders. The sensor
produces a voltage signal that is proportional to the
engine detonation. This information is processed by
the ECM in order to determine detonation levels. To
eliminate detonation, the ECM retards the timing
of the cylinder. If detonation continues, the ECM
will shut down the engine. To observe the value
of the output of the sensors, use Cat ET to view
the “Cylinder #X Detonation Level”. The “X” is the
number for the particular cylinder.
Speed/timing sensor (10) – The engine
speed/timing sensor is located at the rear end of
the left camshaft. The ECM monitors the engine
speed/timing sensor in order to determine the
position of the crankshaft and the engine rpm. With
the position of the crankshaft, the ECM is able to
determine the ignition timing. To observe the engine
speed in rpm, use Cat ET to view the “Engine Speed”
parameter.
23
Systems Operation Section
Table 4
Service Tools
Pt. No.
Description
Functions
Personal Computer (PC)
The PC is required for the use of Cat ET.
“JERD2124”
Software
Single user license for Cat ET
Use the most recent version of the software.
“JERD2129”
Software
Data subscription for all engines
171-4400
Communication Adapter II Gp
This group provides the communication between the PC and the
engine.
7X-1414
Data Link Cable As
This cable connects the communication adapter to the service tool
connector on the engine.
237-7547
Adapter Cable As
This cable connects to the USB port on computers that are not
equipped with a serial port.
146-4080
Digital Multimeter
The multimeter is used for the testing and the adjusting of electronic
circuits.
(1)
(1)
The 7X-1700 Communication Adapter Gp may also be used.
Caterpillar Electronic Technician
(ET)
The Caterpillar Electronic Technician (ET) is designed
to run on a personal computer. Cat ET can display
the following information:
• Parameters
Engine Monitoring System
i02075339
Engine Monitoring System
SMCS Code: 1900; 1901
• Engine configuration
The Electronic Control Module (ECM) monitors the
operating parameters of the engine. The ECM can
initiate a warning or a shutdown if a specific engine
parameter exceeds an acceptable range. Use the
Caterpillar Electronic Technician (ET) to perform the
following activities:
• Status of the monitoring system
• Select the available responses.
Cat ET can perform the following functions:
• Program the level for monitoring.
• Diagnostic tests
• Program delay times for each response.
• Sensor calibration
The default settings for the parameters are
programmed at the factory. To accommodate unique
applications and sites, the parameters may be
reprogrammed with Cat ET. The screens of Cat ET
provide guidance for the changing of trip points.
• Diagnostic codes
• Event codes
• Flash downloading
• Set parameters
Note: Some of the parameters are protected
by factory passwords. Other parameters can be
changed with customer passwords.
Refer to the Troubleshooting Manual for instructions
on troubleshooting events.
Refer to Operation And Maintenance Manual,
“Engine Features And Controls” for additional
information on the default settings.
24
Systems Operation Section
Monitoring Parameters
“Low Oil Filter Differential Pressure”
“Low System Voltage”
The trip point for a warning for this parameter can
be programmed by the customer. The trip point for a
shutdown for this parameter is set at the factory. This
parameter is always ON. This parameter cannot be
turned off. If the engine oil filter differential pressure
decreases to the trip point, the ECM will generate a
warning or a shutdown.
The trip point for this parameter is set at the factory.
The trip point cannot be changed. This parameter
is always ON. This parameter cannot be turned off.
If the system voltage decreases to the trip point or
if the system voltage goes below the trip point, the
ECM will generate a warning or a shutdown.
“High Engine Coolant Temperature”
The trip points for this parameter can be programmed
by the customer. The shutdown response is always
ON. The shutdown response cannot be turned off.
If the engine coolant temperature exceeds the trip
point, the ECM will generate a warning, a derating,
or a shutdown.
“Low Engine Coolant Temperature”
The trip point for this parameter can be programmed
by the customer. If the engine coolant temperature
decreases to the trip point, the ECM will generate
a warning.
“Engine Overspeed”
The trip point for this parameter is set at the factory.
This parameter is always ON. This parameter cannot
be turned off. If the engine speed exceeds the trip
point, the ECM will activate an engine shutdown.
For generator set engines, a typical trip point is 118
percent of the engine’s rated speed.
“High Engine Oil Temperature”
The trip point for a warning for this parameter can
be programmed by the customer. The trip point for
a shutdown is set at the factory. This parameter is
always ON. This parameter cannot be turned off. If
the engine oil temperature exceeds the trip point, the
ECM will generate a warning or a shutdown.
“High Oil Filter Differential Pressure”
The trip point for a warning for this parameter can
be programmed by the customer. The trip point for
a shutdown is set at the factory. This parameter is
always ON. This parameter cannot be turned off.
If the engine oil filter differential pressure exceeds
the trip point, the ECM will generate a warning or a
shutdown.
“High Fuel Temperature”
The trip point for this parameter can be programmed
by the customer. If the fuel temperature exceeds the
trip point, the ECM will generate a warning.
“Low Fuel Pressure”
The trip point for this parameter can be programmed
by the customer. If the fuel pressure decreases to the
trip point, the ECM will generate a warning.
“High Eng Oil to Eng Coolant Diff Temp”
The trip point for a warning for this parameter can
be programmed by the customer. The trip point for a
shutdown for this parameter is set at the factory. The
shutdown response is always ON. The shutdown
response cannot be turned off. If the differential
temperature of the engine oil to the jacket water
exceeds the trip point, the ECM will generate a
warning or a shutdown.
“Low Gas Fuel Differential Pressure”
The trip point for this parameter can be programmed
by the customer. If the fuel differential pressure
decreases to the trip point, the ECM will generate
a warning.
“High Gas Fuel Differential Pressure”
The trip point for this parameter can be programmed
by the customer. If the fuel differential pressure
exceeds the trip point, the ECM will generate a
warning.
“High System Voltage”
The trip point for this parameter is set at the factory.
The trip point cannot be changed. This parameter is
always ON. This parameter cannot be turned off. If
the system voltage exceeds the trip point, the ECM
will generate a warning.
25
Systems Operation Section
Trip Points of the Engine Load for High
Inlet Air Temperature
The trip points for this parameter can be programmed
by the customer. The shutdown response is always
ON. The shutdown response cannot be turned off.
This feature provides a trip point between high engine
load and low engine load. The trip point is used for
events that involve high inlet air temperature. The trip
point for the events is based on the engine load. The
possible responses of the system include warning,
derating, and shutdown.
If the load is greater than the trip point, the trip point
for the “High Inlet Air Temperature at High Engine
Load” event is used for the logging of the high inlet
air temperature.
If the load is less than the trip point, the trip point
for the “High Inlet Air Temperature at Low Engine
Load” event is used for the logging of the high inlet
air temperature.
“High Inlet Air Temperature at Low
Engine Load”
The conditions are designed to eliminate false events
during start-up if the customer has programmed a
delay time to zero.
If the trip point for a shutdown is programmed to
activate before the trip point for a warning, the engine
will shut down and the warning will not be activated.
Ignition System
i02077064
Ignition System
SMCS Code: 1550
G3516
The engine is equipped with an electronic ignition
system. The system provides dependable firing
and low maintenance. The system provides precise
control of the spark and of the ignition timing for each
cylinder.
The “Service/Configuration” screen of Cat ET defines
the “High Inlet Air Temp Engine Load Set Point”.
The ECM can activate a warning, a derating, or a
shutdown if the inlet air temperature exceeds the trip
point during the low load operation that is defined.
“High Inlet Air Temperature at High
Engine Load”
The “Service/Configuration” screen of Cat ET defines
the “High Inlet Air Temp Engine Load Set Point”.
The ECM can activate a warning, a derating, or a
shutdown if the inlet air temperature exceeds the trip
point during the high load operation that is defined.
“High Fuel Pressure”
The trip point for this parameter can be programmed
by the customer. The ECM will activate a warning if
the fuel pressure exceeds the trip point.
Illustration 14
g01063377
Conditions for Parameters
(1) Electronic Control Module (ECM)
(2) Ignition transformer
Some of the programmable parameters are
dependent on the status of an ECM output before
the parameters are allowed to function. Some of the
parameters are allowed to function after the crank
terminate relay has been energized for more than 30
seconds. Other parameters are allowed to function
after the output for the fuel control relay is energized.
Some parameters are not dependent upon any
conditions.
Each cylinder has an ignition transformer. The ECM
controls ignition on the left bank and on the right
bank. To initiate combustion, the ECM sends a pulse
of approximately 100 volts to the primary coil of each
ignition transformer at the appropriate time and for
the appropriate duration. The transformers step up
the voltage in order to create a spark across the
spark plug electrode.
26
Systems Operation Section
Detonation sensors monitor the engine for detonation.
The G3516 Engine has eight detonation sensors.
Each sensor monitors two adjacent cylinders. The
sensors generate data on vibration that is processed
by the ECM in order to determine detonation levels.
If detonation occurs, the ECM retards the ignition
timing of the affected cylinder or cylinders up to six
degrees. If a cylinder has been fully retarded for five
seconds and the cylinder is still detonating, the ECM
shuts down the engine.
The ECM provides extensive diagnostics for the
ignition system.
G3520
The engine is equipped with an electronic ignition
system. The system provides dependable firing
and low maintenance. The system provides precise
control of the spark and of the ignition timing for each
cylinder.
Illustration 15
g00926741
(1) Master Electronic Control Module (ECM)
(2) Slave ECM
(3) Ignition transformer
Each cylinder has an ignition transformer. The
master ECM controls ignition on the left bank and
the slave ECM controls ignition on the right bank.
To initiate combustion, each ECM sends a pulse of
approximately 100 volts to the primary coil of each
ignition transformer at the appropriate time and for
the appropriate duration. The transformers step up
the voltage in order to create a spark across the
spark plug electrode.
Detonation sensors monitor the engine for detonation.
The G3520 Engine has ten detonation sensors. Each
sensor monitors two adjacent cylinders. The sensors
generate data on vibration that is processed by each
ECM in order to determine detonation levels. The
master ECM monitors the sensors on the left bank
and the slave ECM monitors the sensors on the right
bank. The slave ECM communicates the status of
the right side sensors to the master ECM.
If detonation occurs, the master ECM retards the
ignition timing of the affected cylinder or cylinders up
to six degrees. If a cylinder has been fully retarded
for five seconds and the cylinder is still detonating,
the ECM shuts down the engine.
Each ECM provides extensive diagnostics for the
ignition system.
Ignition Transformers and Spark
Plugs
Illustration 16
(1)
(2)
(3)
(4)
(5)
(6)
g00926743
Mounting flange
Ignition transformer
Primary connection
Spark plug
Extension
Hole in the spark plug’s precombustion chamber
Mounting flange (1) provides a ground for each
transformer (2). The ignition harness is connected
to primary connection (3). The output from the
secondary circuit of the transformer is sent to
spark plug (4) through the secondary connection in
extension (5).
27
Systems Operation Section
The spark plug does not have a conventional
electrode gap that can be adjusted. The spark
plug has a precombustion chamber. During the
compression stroke, the air/fuel mixture in the cylinder
enters holes in the spark plug’s precombustion
chamber. The secondary circuit of the transformer
provides an initial 8,000 to 32,000 V to the spark
plug in order to create a spark. The air/fuel mixture
ignites in the spark plug’s precombustion chamber.
A pattern of multiple flames exit the spark plug’s
precombustion chamber through the holes in order to
ignite the air/fuel mixture in the cylinder.
Fuel System
i02077093
Fuel System Operation
SMCS Code: 1250
The Electronic Control Module (ECM) provides
control of the air/fuel mixture to the engine.
Illustration 17 is a diagram of the fuel system’s main
components. The flow of fuel through the system is
explained below.
Illustration 17
g00925482
The fuel flows from the main gas supply through
the fuel filter. Usually, the fuel filter is a component
of the design at the particular site. The customer is
responsible for supplying clean, dry fuel to the engine.
The fuel filter may be supplied by Caterpillar or by
the customer. To prevent particles from entering the
engine, a one micron filter is recommended. The filter
must be properly sized for the required gas pressure.
For installation of the fuel filter, the recommended
location is close to the engine before the engine’s
gas pressure regulator. Pressure gauges in the gas
lines on each side of the fuel filter are recommended
in order to monitor the filter’s differential pressure. A
manual shutoff valve in the gas line before the fuel
filter will facilitate servicing of the filter.
28
Systems Operation Section
The filtered fuel flows to the Gas Shutoff Valve
(GSOV). The GSOV may be supplied by Caterpillar
or by the customer. The solenoid for the GSOV may
be connected to engine’s wiring harness or to a
harness that is supplied by the customer. In either
case, the customer may install a switch that can
interrupt the circuit.
The control system is configured for a GSOV that is
energize-to-run. This means that the GSOV must be
energized in order for the engine to run. The GSOV
may be energized by the customer’s equipment or by
the ECM. When the GSOV is energized, the valve
opens and the fuel flows to the engine. When the
control system shuts down the engine, the voltage is
removed from the solenoid. The valve closes and
the fuel is shut off.
The fuel flows through the GSOV to the gas
pressure regulator. The regulator may be supplied by
Caterpillar or by the customer. A regulated pressure
of 7 to 35 kPa (1 to 5 psi) is recommended. Less
pressure may result in reduced power. More pressure
may result in instability.
Illustration 19
g00925717
Top view
Fuel flow through the 60 Hz arrangement
(1) Fuel metering valve
The fuel flows to the electronically controlled fuel
metering valve (1). The ECM issues a command
signal to the fuel metering valve via the CAN data
link. The fuel metering valve regulates the flow of fuel
to the engine.
Illustration 18
Top view
Flow of fuel through the 50 Hz arrangement
(1) Fuel metering valve
g00925714
29
Systems Operation Section
Illustration 22
g00925773
Right view
Flow of fuel and of air through the 50 Hz arrangement
(4) Throttle
(5) Aftercooler
Illustration 20
g00925730
Right view
Flow of fuel and of air through the 50 Hz arrangement
(2) Air inlet elbow’s adapter
(3) Turbocharger’s compressor
Illustration 23
g00925776
Right view
Flow of fuel and of air through the 60 Hz arrangement
(4) Throttle
(5) Aftercooler
The compressed air/fuel mixture flows to the
electronically controlled throttle (4). The ECM issues
a command signal to the throttle’s actuator via the
CAN data link. The signal is based on the desired
engine speed. The throttle controls the volume of the
air/fuel mixture that flows through aftercooler (5).
Illustration 21
g00925767
Right view
Flow of fuel and of air through the 60 Hz arrangement
(2) Air inlet elbow’s adapter
(3) Turbocharger’s compressor
The fuel metering valve controls the volume of fuel
that flows to adapter (2) for the air inlet elbow. The
inlet air that is necessary for combustion also enters
the adapter. The air/fuel mixture enters turbocharger
compressor (3).
The temperature of the compressed air/fuel mixture
is reduced in the aftercooler. This increases the
density of the air/fuel mixture. This results in more
efficient combustion.
30
Systems Operation Section
Illustration 24
g00925819
Flow of air and fuel through the air inlet manifold
(5) Aftercooler
(6) Air inlet manifold
The air/fuel mixture flows from the aftercooler through
air inlet manifold (6). The manifold distributes the
air/fuel mixture to the cylinders for combustion.
i02079671
Air/Fuel Ratio Control
SMCS Code: 1278
The Electronic Control Module (ECM) provides
control of the air/fuel mixture for performance and
for efficiency at low emission levels. The system
includes the following components: maps in the
ECM, output drivers in the ECM, inlet manifold
pressure sensor, inlet manifold temperature sensor,
engine speed/timing sensor, wattmeter, and fuel
metering valve. Additionally, the customer’s input
via the Caterpillar Electronic Technician (Cat ET) is
required. Illustration 25 is a diagram of the system’s
main components and of the inputs for the system.
31
Systems Operation Section
g01019236
Illustration 25
Cat ET – This software is designed to run on
a personal computer. Technicians can use the
program to perform many functions. For the air/fuel
ratio control, the technician programs configuration
parameters into the ECM.
Inlet manifold temperature sensor – This sensor
monitors the temperature of the air/fuel mixture in
the air inlet manifold.
Inlet manifold pressure sensor – This sensor
monitors the pressure of the air/fuel mixture in the air
inlet manifold.
Engine speed/timing sensor – This sensor
monitors the rotation of a speed-timing wheel in order
to provide information on the engine timing and on
the engine rpm.
Wattmeter – The engine’s control system requires
an input which indicates the generator’s output
in kilowatts. This input can be from the following
components: EMCP II+, programmable logic
controller (PLC), and wattmeter. The equipment
that monitors the generator’s output is provided by
the customer if the EMCP II+ is not used. The PLC
or the wattmeter must provide an analog signal
within the range of 0 to 5 volts. The output must
have a linear relationship with the generator’s actual
output in electrical kilowatts (ekW). The output must
be accurate within 0.5 percent of the generator’s
actual current. The out put must use as much the
acceptable range as possible.
Fuel metering valve – This is an electronically
controlled actuator and a valve that regulates the flow
of fuel. The device monitors the fuel temperature, the
fuel pressure, and the valve’s differential pressure.
The ECM sends a command signal for the fuel flow to
the device. The device modulates the valve in order
to match the command signal.
The ECM communicates with the fuel metering valve
via the CAN Data Link.
The air/fuel ratio control has two basic modes of
operation:
• Open loop
• Charge density feedback
The modes of operation are explained below.
For proper operation of the air/fuel ratio control, input
from the customer is necessary.
Input from the Customer
To accurately control the air/fuel ratio, the control
system depends on input from the customer.
Before the initial start-up, a current gas analysis is
required. Data from the gas analysis must be entered
into Caterpillar Software, LEKQ6378, “Methane
Number Program”. The results are programmed into
the ECM.
32
Systems Operation Section
Note: It is very important to use the Caterpillar
Software, LEKQ6378, “Methane Number
Program”. Use of only the data from the gas analysis
can result in incorrect settings.
The following parameters are programmed into the
ECM via the “Configuration” screen of Cat ET:
• “Fuel Quality”
• “Gas Specific Gravity”
• “Fuel Specific Heat Ratio”
• Four inputs for the engine load
Note: For more details on these topics, refer to
Systems Operation/Testing and Adjusting, “Electronic
Control System Parameters”.
“Fuel Quality” – This is the fuel’s Low Heating
Value (LHV). The value is obtained from a fuel
analysis which is entered into Caterpillar Software,
LEKQ6378, “Methane Number Program”.
During operation, the ECM uses the LHV to help
determine the command signal for the fuel flow.
“Gas Specific Gravity” – This is the fuel’s specific
gravity in relation to the specific gravity of air. The
value is obtained from a fuel analysis which is entered
into Caterpillar Software, LEKQ6378, “Methane
Number Program”.
“Fuel Specific Heat Ratio” – This is a ratio of the
fuel’s specific heat at a constant pressure and at a
constant volume.
The ECM provides the fuel’s specific gravity and heat
ratio to the fuel metering valve via the CAN data link.
The fuel metering valve uses this information to help
regulate the fuel flow.
In addition to the information on the fuel, the ECM
requires information on the engine load.
Engine Load
The ECM must have values for the following
parameters. The parameters are entered into the
ECM via Cat ET.
• “Engine Output Power Configuration”
• “Engine Driven Accessory Load Configuration”
• “Generator Output Power Sensor Scale Factor”
• “Generator Output Power Sensor Offset”
“Engine Output Power Configuration” – This is
the engine’s full load rating in ekW. The rating is
stamped on the engine’s Information Plate.
“Engine Driven Accessory Load Configuration” –
This is the load of the auxiliary equipment such as a
radiator fan that is directly driven by the engine.
“Generator Output Power Sensor Scale Factor” –
This is a scale for the wattmeter’s output.
If the generator is equipped with the EMCP II+,
information on the generator’s electrical power output
is provided to the ECM via the CAT data link. The
ECM is correctly programmed at the factory for the
“Generator Output Power Sensor Scale Factor”
and the “Generator Output Power Sensor Offset”
parameters. No further adjustment is necessary for
the parameters.
If the generator is not equipped with the EMCP II+,
information on the engine load must be provided
by a customer supplied wattmeter. The wattmeter’s
output to the ECM must be an analog signal within
the range of 0 to 5 volts. A voltage that is near 0.2
VDC indicates that the generator has a low power
output. A voltage that is near 4.8 VDC indicates that
the generator has a high power output.
Because there are different wattmeters, the scale for
the wattmeter’s output must be entered into the ECM.
The scale provides a linear relationship between
the wattmeter’s voltage output and the generator’s
electrical power output. The scale corresponds to the
wattmeter’s output.
“Generator Output Power Sensor Offset” – The
offset is used to make the wattmeter’s scale accurate.
Because the output from different wattmeters can
vary, an offset for the wattmeter must also be entered
into the ECM. The offset can be a positive value or a
negative value.
All of the above parameters are programmed into the
ECM via the “Configuration” screen of Cat ET. For
more details, refer to Systems Operation/Testing and
Adjusting, “Electronic Control System Parameters”.
Open Loop Mode
Open loop – During operation in this mode, the
ECM controls the air/fuel ratio with maps and with
calculations for the desired air/fuel ratio. This mode
of operation uses no feedback. The air/fuel ratio is
controlled in the open loop mode from start-up until
the engine load becomes greater than 25 percent.
33
Systems Operation Section
The ECM uses a Fuel Correction Factor (FCF) to
help determine the fuel flow. During operation in the
open loop mode, the FCF is always 1. This enables
the customer programmable “Fuel Quality” or LHV
to affect the air/fuel ratio.
Air Inlet and Exhaust
System
i01815531
To richen the air/fuel mixture, reduce the LHV.
The ECM will compensate for the reduced LHV by
increasing the fuel flow.
Aftercooler
SMCS Code: 1063
To lean the air/fuel mixture, increase the LHV. The
ECM will compensate for the increased LHV by
reducing the fuel flow.
Charge Density Feedback
Charge density – This is the density of the air/fuel
mixture in the air inlet manifold.
Charge density feedback – The ECM calculates
the actual charge density. The actual charge density
is compared to the desired charge density. To
achieve the desired charge density, the ECM sends a
command signal to the fuel metering valve. This is a
continuous process during operation with loads that
are greater than 25 percent.
The same customer’s inputs that are required
for operation in the open loop are used for the
feedback mode. In addition, the following additional
configuration parameter must be programmed into
the ECM via the “Configuration” screen of Cat ET:
“Desired Emission Gain Adjustment” – This is
an adjustment for the charge density. To richen the
air/fuel mixture, increase the gain adjustment. To lean
the air/fuel mixture, decrease the gain adjustment.
The ECM uses the gain adjustment to help determine
the FCF. The FCF varies during operation in the
feedback mode.
Note: A small change in the “Desired Emission Gain
Adjustment” causes a large change in the actual
exhaust emissions. For example, an adjustment of
one percent in the parameter’s value will result in a
change of 20 to 40 ppm in the actual level of NOx.
Illustration 26
g00926747
Flow of the air/fuel mixture through the aftercooler
(1) First stage
(2) Second stage
The aftercooler is located on top of the engine. The
aftercooler has a two-stage core assembly. Coolant
from the jacket water circuit flows through first
stage (1) of the aftercooler core. Coolant from the
separate circuit flows through second stage (2) of
the aftercooler core.
Note: For some engines that are used for
cogeneration, the aftercooler’s first stage may also
be separate.
The air/fuel mixture from the turbocharger’s
compressor flows through the throttle into the
aftercooler’s cover. The air/fuel mixture passes
through the fins of the aftercooler core in order to
exchange heat with the coolant. The temperature of
the compressed air/fuel mixture is reduced in the
aftercooler. This increases the density of the air/fuel
mixture. This results in more efficient combustion.
The temperature of the air/fuel mixture is initially
reduced in the first stage. The second stage provides
further reduction of the air/fuel mixture’s temperature.
The air/fuel mixture from the aftercooler is distributed
through the air inlet manifold to the cylinders for
combustion.
34
Systems Operation Section
i01815635
Compressor Bypass
SMCS Code: 1050
A rapid reduction in the generator’s power output
can cause a rapid increase in the engine speed. The
increased engine speed causes the turbocharger to
produce boost pressures that are greater than the
requirement for the engine operation.
Turbocharger surge – In response to the excess
pressure in the air inlet system, the flow of air across
the turbocharger compressor wheel is reversed.
This reversal of the air flow is called a turbocharger
surge. During a turbocharger surge, the turbocharger
overspeeds temporarily. This places a greater axial
load on the thrust bearing and higher than normal
torque on the shaft. The turbocharger surge can
result in severe damage to the turbocharger.
The compressor bypass group reduces the
opportunity for a turbocharger surge.
Illustration 27
Flow of the compressed air/fuel mixture during activation of the compressor bypass group (50 Hz arrangement)
(1)
(2)
(3)
(4)
(5)
Actuator for the bypass valve
Bypass valve
Throttle
Throttle actuator
Fuel metering valve
g00926843
35
Systems Operation Section
The master Electronic Control Module (ECM)
monitors the engine speed. The ECM responds to
a rapid increase in the engine speed by sending a
command signal to actuator (1). This causes the
actuator to move a shaft that is connected to a plate
inside bypass valve (2). The bypass valve opens.
i01818154
Exhaust Manifold
SMCS Code: 1059
The bypass valve is connected before throttle (3).
Tubing is connected from the bypass valve to the inlet
for the turbocharger compressor. When the bypass
valve is opened, the compressed air/fuel mixture is
diverted through the tubing away from the throttle.
This reduces the back pressure that is caused by
excessive pressure in the air inlet system.
Note: The bypass valve for the 60 Hz arrangement
is connected to two sets of tubing: one set of tubing
is connected to the inlet for the right turbocharger
and the other set of tubing is connected to the inlet
for the left turbocharger.
Additionally, the ECM sends two other command
signals. A command to throttle actuator (4) opens
the throttle in order to reduce the resistance that
contributes to back pressure. A command to fuel
metering valve (5) reduces the fuel supply in order
to reduce the engine speed and the turbocharger’s
speed.
The combined effect of these actions reduces the
opportunity for a turbocharger surge.
Illustration 28
g00928158
Flow of exhaust gas through the exhaust manifolds (50 Hz
arrangement)
The 50 Hz arrangement has one turbocharger.
The ECM determines a time period that is required
for opening of the bypass valve. After the time period
has expired, the ECM sends a command signal
to actuator (1) in order to close the bypass valve.
Normal operation resumes.
The compressor bypass group is also operated
during engine shutdown. This reduces the opportunity
for a turbocharger surge during engine shutdown.
Additionally, any air/fuel mixture that may have been
trapped in the tubing is purged.
Illustration 29
g00928159
Flow of exhaust gas through the exhaust manifolds (60 Hz
arrangement)
The 60 Hz arrangement has two turbochargers.
The exhaust manifolds are located on the sides of
the engine. Exhaust gas flows from each cylinder
head through intermediate exhaust manifolds that
are connected by bellows in order to form a passage
to the turbocharger turbine.
36
Systems Operation Section
The dry exhaust manifolds provide maximum heat to
the turbine. The exhaust manifolds are covered with
insulated heat shields in order to retain the heat. The
heat shields also help protect the wiring and other
components from the heat.
i01793967
The bearing housing in the turbocharger is also
cooled by the jacket water coolant. Coolant from the
coolant inlet line enters the side of the center section.
The coolant travels through the coolant passages
(8) in the bearing housing. The coolant then leaves
the turbocharger at the opposite side of the center
section.
Turbocharger
i01784356
Valve System Components
SMCS Code: 1052
The turbine side of the turbocharger is mounted to
the exhaust manifold. The compressor side of the
turbocharger is connected by pipes to the aftercooler
housing.
Illustration 30
SMCS Code: 1105
The valve system components control the flow of the
inlet air and of the fuel into the cylinders and the flow
of exhaust gas out of the cylinders during engine
operation.
g00281664
Turbocharger (typical example)
(1) Compressor wheel
(2) Bearing
(3) Oil inlet
(4) Bearing
(5) Turbine wheel
(6) Exhaust outlet
(7) Air inlet
(8) Coolant passages
(9) Oil outlet
(10) Exhaust inlet
The exhaust gases go into the exhaust inlet (10)
of the turbine housing. The gases push the blades
of turbine wheel (5). The turbine wheel and the
compressor wheel turn at speeds up to 90,000 rpm.
Air and fuel are pulled through the compressor
housing air inlet (7) by the rotation of the compressor
wheel (1). The action of the compressor wheel blades
causes a compression of the air/fuel mixture.
Bearing (2) and bearing (4) in the turbocharger use
engine oil under pressure for lubrication. The oil is
sent through the oil inlet line to oil inlet (3) at the top.
The oil then goes through passages in the center
section for lubrication of the bearings. The oil goes
out of oil outlet (9) at the bottom. The oil then goes
back to the engine block through the drain line.
Illustration 31
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
g00813876
Rocker arm
Valve bridge
Valve rotator
Valve spring
Pushrod
Valve
Cam follower
Camshaft lobe
The crankshaft gear drives the camshaft gears
through idler gears. The camshafts must be timed
to the crankshaft in order to get the correct relation
between the movement of the piston and movement
of the valves.
37
Systems Operation Section
The camshafts have two camshaft lobes (8) for each
cylinder. As the camshaft turns, the camshaft lobe
causes cam follower (7) and pushrod (5) to move up
and down.
The pushrod moves rocker arm (1). Movement of the
rocker arm causes valve bridge (2) to move up and
down on a dowel in the cylinder head. This movement
operates valves (6). The valve bridge enables one
rocker arm to operate two valves simultaneously.
There are two inlet valves and two exhaust valves for
each cylinder.
Valve rotator (3) turns the valve during engine
operation. The rotation of the valves keeps the
deposit of carbon on the valves to a minimum. This
provides longer service life for the valves.
When cam follower (7) moves downward, valve
spring (4) closes the valve.
38
Systems Operation Section
Lubrication System
i01819296
Lubrication System
SMCS Code: 1300
g00928770
Illustration 32
Lubrication system schematic (typical example)
(1) Main engine oil gallery
(2) Engine oil gallery for the left camshaft
(3) Engine oil gallery for the right camshaft
(4) Engine oil gallery for the piston cooling
jets
(5) Piston cooling jet
(6) Engine oil supply for the turbochargers
(7) Sequence valve
(8) Sequence valve
(9) Adapter
(10) Engine oil filter base
(11) Engine oil cooler
Engine oil pump (14) has three gears that are driven
by the front gear train. The engine oil pump pulls
engine oil from the pan through suction bell (16) and
elbow (15). The suction bell has a screen in order to
strain the engine oil.
(12)
(13)
(14)
(15)
(16)
(17)
Bypass valve
Relief valve
Engine oil pump
Elbow
Suction bell
Engine oil filter
Relief valve (13) controls the maximum pressure
of the engine oil from the engine oil pump. If the
pressure from the pump becomes excessive, the
relief valve opens and some of the engine oil returns
to the engine oil pan.
Engine oil cooler (11) reduces the temperature of the
engine oil. The engine oil cooler has bypass valve
(12) that is designed to open if the cooler becomes
restricted.
39
Systems Operation Section
Illustration 33
g00928818
(10) Engine oil filter base
(17) Engine oil filter housing
Engine oil filter base (10) provides the mount for
engine oil filters (17). The base has an internal
bypass valve.
The bypass valve will open if there is a restriction in
the engine oil cooler or in the engine oil filter. This
allows the engine to be lubricated if the engine oil
cooler is plugged or if the engine oil filter is dirty.
Clean engine oil from the engine oil filters goes
through adapter (9) into the block. Part of the engine
oil goes to left camshaft oil gallery (2). The remainder
of the engine oil goes to main engine oil gallery (1).
Illustration 34
g00928859
(5) Piston cooling jet
Piston cooling jet (5) is located in the engine block
below each piston. Each piston cooling jet has two
tubes with open ends. One tube directs engine oil
into an opening in the bottom of the piston for an
engine oil gallery in the piston. This gallery provides
cooling oil behind the ring band of the piston. The
gallery provides engine oil to a slot (groove) in
the side of both piston pin bores. The other tube
directs engine oil to the center of the piston. This
provides lubrication to the piston pin and to the piston
undercrown. This also helps cool the piston.
Engine oil galleries (2) and (3) supply engine oil
through drilled passages to the camshaft bearings.
The engine oil circulates around each camshaft
journal. The engine oil then flows through the cylinder
head and through the rocker arm housing to the
rocker arm shaft. Some of the engine oil lubricates
the valve stems. The remainder of the engine oil
drains from the cylinder head in order to lubricate the
pushrods, the valve lifters, the camshaft, and the
camshaft bearings.
Engine oil from main engine oil gallery (1) is supplied
to the main bearings through drilled passages. Drilled
holes in the crankshaft supply engine oil from the
main bearings to the connecting rod bearings. Engine
oil from the rear of the main engine oil gallery goes to
the rear of right camshaft oil gallery (3).
Sequence valves (7) and (8) allow engine oil from
main engine oil gallery (1) to enter engine oil galleries
(4) for piston cooling jets (5). The sequence valves
will not allow engine oil into gallery (4) for the piston
cooling jets until there is pressure in the main engine
oil gallery. This reduces the amount of time that is
required for pressure buildup when the engine is
started.
Illustration 35
g00928860
Lines for engine oil
(6) Supply line
(18) Drain line
Supply line (6) provides engine oil for lubrication
of the turbocharger bearings. The engine oil flows
through drain line (18) into the front housing.
40
Systems Operation Section
Engine oil is provided to the front and rear gear
groups through drilled passages in the front housings,
in the rear housings, and in the faces of the cylinder
block. These passages are connected to engine oil
galleries (2) and (3) for the camshafts.
After the oil has completed lubrication, the engine oil
returns to the engine oil pan.
Cooling System
i01819715
Cooling System
SMCS Code: 1350
The engine has two cooling systems. The jacket water
system cools the following components: engine oil
cooler, cylinder block, cylinder heads, turbochargers,
and aftercooler’s first stage. A separate system cools
the aftercooler’s second stage. Illustration 36 is a
diagram of the typical cooling system.
41
Systems Operation Section
g00811028
Illustration 36
The cooling system has two pumps that are driven by the engine. Coolant from the jacket water cools the first stage of the aftercooler. The
separate circuit cools the second stage.
Water temperature regulators are used in each circuit
in order to maintain correct operating temperatures.
Jacket Water System
The jacket water pump is located on the right front
side of the engine. The water pump has a gear that
is driven by the lower right front gear group. Coolant
from the radiator or the heat exchanger enters the
water pump’s inlet. The rotation of the impeller in the
jacket water pump pushes the coolant through the
system.
42
Systems Operation Section
The flow of the coolant is divided. Some of the
coolant from the jacket water pump flows through
a tube to the front of the cylinder block and into the
main distribution manifold for the water jacket of each
cylinder. The remainder of the coolant flows through
the engine oil cooler.
After flowing through the engine oil cooler, this portion
of the coolant is divided again. Some of the coolant
flows into the water jacket of the right rear cylinder.
This coolant is mixed throughout the engine’s water
jacket with the coolant that flows to the front of the
cylinder block. The remainder of the coolant flows
through the first stage of the aftercooler.
The coolant inside the cylinder block flows around
the cylinder liners. The water jacket is smaller near
the top of the cylinder liners. This shelf causes the
coolant to flow faster for better cooling of the cylinder
liner. The coolant is pumped up through water
directors into the cylinder heads. The coolant flows
through passages around these items in the cylinder
head: valves, valve seat inserts, spark plug adapter,
and exhaust outlets.
The coolant exits the cylinder heads through tubes
and the coolant flows into the water manifold.
Coolant flows through the water manifold into lines
for the turbocharger turbine housing. The coolant
returns to the water manifold.
Air is vented from the high points of the cooling
system. The vent line from the connection must be
straight and the vent line must have a slight upward
slope. The vent must not be obstructed.
The water manifold directs the coolant to the water
temperature regulator housing. The engine has eight
water temperature regulators. The water temperature
regulators control the direction of the coolant flow
according to the coolant temperature.
When the coolant achieves normal operating
temperature, the water temperature regulators open
and coolant flow is divided. Most of the coolant goes
through the radiator or through the heat exchanger.
This coolant circulates back to the jacket water pump.
The remainder of the coolant goes through a bypass
tube to the jacket water pump.
Note: The water temperature regulators are
necessary to maintain the correct engine
temperature. If the water temperature regulators are
not installed in the system, there is no mechanical
control. Most of the coolant will take the path of
least resistance through the bypass tube. This will
cause the engine to overheat in hot weather. The
small amount of coolant that goes through the
radiator in cold weather will not allow the engine
to achieve normal operating temperatures. The
water temperature regulators control the minimum
temperature of the coolant. The radiator or the heat
exchanger controls the maximum temperature of the
coolant.
The bypass tube has another function. When you
fill the cooling system the internal bypass allows
the coolant to go into the cylinder head and into the
cylinder block without going through the water pump.
The total system capacity depends on the amount of
coolant in the cylinder block, in the piping, and in the
radiator or heat exchanger.
43
Systems Operation Section
Separate Circuit
g00929351
Illustration 37
(1) Auxiliary water pump
(2) Tube for the coolant supply to the
aftercooler’s second stage
(3) Aftercooler
(4) Tube for the coolant return from the
aftercooler to the thermostatic valve
(5) Thermostatic valve
(6) Outlet for coolant to the radiator or heat
exchanger
(7) Inlet for coolant from the radiator or heat
exchanger
Auxiliary water pump (1) is driven by the engine’s
auxiliary drive. The coolant is pumped through
tube (2) to the aftercooler’s second stage (3). The
coolant exits the aftercooler through tube (4) that is
connected to thermostatic valve (5).
The thermostatic valve has one inlet, two outlets,
and a water temperature regulator. When the coolant
is cool, the water temperature regulator is closed.
The coolant is routed directly back to the auxiliary
water pump. The coolant is recirculated through the
aftercooler.
When the coolant reaches the opening temperature,
the water temperature regulator opens. The coolant
is to a radiator or to a heat exchanger through outlet
(6). The coolant returns to the auxiliary pump through
inlet (7).
Basic Engine
i01794011
Cylinder Block, Liners and
Heads
SMCS Code: 1100; 1200
The cylinders in the left side of the block form a 60
degree angle with the cylinders in the right side.
44
Systems Operation Section
Illustration 40
g00807727
(8) Exhaust valves
(9) Inlet valves
(10) Gasket
(11) Water seals
Illustration 38
(1)
(2)
(3)
(4)
(5)
g00807706
Cylinder liner
Filler band
O-ring seals
Main bearing cap
Bolt
Cylinder liners (1) can be removed for replacement.
The top surface of the cylinder block is the seat for
the cylinder liner flange. Engine coolant flows around
the cylinder liners in order to keep the cylinder liners
cool. Filler band (2) and three O-ring seals (3) seal
the coolant in the cylinder block.
Main bearing caps (4) are fastened to the cylinder
block with four bolts (5) per cap.
Illustration 39
Each cylinder head has four valves. Two exhaust
valves (8) and two inlet valves (9) are controlled by
a camshaft and pushrods. For information on the
operation of the valves, refer to Systems Operation,
“Valve System Components”. Valve guides are
pressed into the cylinder heads. The spark plug is
located between the four valves.
Another gasket (10) on top of the spacer plate seals
the oil drain passages between the cylinder head
and the spacer plate. After the engine oil lubricates
the components in the cylinder head, the engine oil
drains back into the engine block.
Coolant flows from the cylinder block into the cylinder
head through water seals (11). The coolant flows
through passages in the cylinder head. The coolant
exits the cylinder head and flows into the water
manifold.
g00807723
(6) Spacer plate
(7) Gasket
The engine has a separate cylinder head for each
cylinder. An aluminum spacer plate (6) and gasket
(7) is between each cylinder head and the cylinder
block. The plate and the gasket accommodate the
thickness of the cylinder liner flange.
Illustration 41
(12) Camshaft cover
(13) Crankcase cover
g00807743
45
Systems Operation Section
Camshaft covers (12) allow access to the camshaft
and valve lifters. Crankcase covers (13) allow access
to the crankshaft connecting rods, main bearings,
and piston cooling jets.
i02086032
Crankshaft
SMCS Code: 1202
i01794015
Pistons, Rings and Connecting
Rods
SMCS Code: 1214; 1218
Illustration 43
g00929004
Crankshaft
The crankshaft changes the reciprocating motion of
the pistons into usable rotating torque.
The crankshaft drives a group of gears on the front
and on the rear of the engine. The front gear group
drives the engine oil pump, the jacket water pump,
and the accessory drives. The rear gear group drives
the camshafts.
Illustration 42
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
g00807790
Piston
Compression rings
Oil ring
Connecting rod
Piston pin
Pin retainer
Bolt
Connecting rod cap
Connecting rod bearing
Aluminum pistons (1) have three rings. The rings
include two compression rings (2) and one oil ring
(3). All the rings are located above the piston pin
bore. The top two compression rings are rectangular.
The oil ring is a two-piece ring. Engine oil returns to
the crankcase through holes in the oil ring groove.
The piston is attached to connecting rod (4) with
piston pin (5) and with two pin retainers (6). The
connecting rod has a taper on the pin bore end. This
taper gives the connecting rod and the piston more
strength in the areas with the most load. Four bolts
(7), which are set at a small angle, hold connecting
rod cap (8) to the connecting rod. This design keeps
the connecting rod width to a minimum, so that a
larger connecting rod bearing (9) can be used and
the connecting rod can still be removed through the
cylinder liner.
Pressurized engine oil is supplied to the crankshaft’s
main bearings through drilled passages in the webs
of the cylinder block. The engine oil then flows
through drilled passages in the crankshaft in order to
provide lubrication to the connecting rod bearings.
The G3516 Engine has nine main bearings. Two
thrust plates on the sides of the center main bearing
control the end play of the crankshaft.
The G3520 Engine has 11 main bearings. Two thrust
plates on the sides of the rear main bearing control
the end play of the crankshaft.
Illustration 44
Cross sections of the crankshaft seals and wear sleeves
g00807826
46
Systems Operation Section
Seals and wear sleeves are used at both ends of
the crankshaft. Engine oil is sealed by the lip seals
and the wear sleeves help prevent wear on the
crankshaft.
The engine has two-piece camshafts. Dowel (1) in
one section of the camshaft goes through spacer (2)
into the other section of the camshaft. The sections
are joined by bolts (3). Each camshaft is supported by
nine bearings for the G3516 Engine. Each camshaft
is supported by 11 bearings for the G3520 Engine.
As the camshaft turns, each lobe moves a lifter
assembly. There are two lifter assemblies for each
cylinder. Each lifter assembly moves a pushrod and
two inlet valves or two exhaust valves. The camshafts
must be timed with the crankshaft. The relation of the
camshaft lobes to the crankshaft position cause the
valves in each cylinder to operate at the correct time.
Illustration 45
g00929007
Side view of the vibration damper
A vibration damper is bolted to the front of the
crankshaft in order to reduce torsional vibrations that
can cause damage to the engine.
i02086856
Camshaft
SMCS Code: 1210
The engine has two camshafts. The camshafts are
driven by the gears at the rear of the engine.
Illustration 46
Connections for the two-piece camshaft
(1) Dowel
(2) Spacer
(3) Bolt
g00807910
47
Systems Operation Section
Air Starting System
i01917455
Air Starting System
SMCS Code: 1450
g01013593
Illustration 47
Air starting system (typical example)
(1) Relay valve
(2) Hose
(3) Starting motor solenoid
(4) Hose
(5) Air starting motor
When the main supply of pressurized air is ON,
pressurized air is provided to relay valve (1). The
main supply of pressurized air is blocked by the
relay valve. The relay valve allows some control air
pressure to flow through hose (2) from the bottom of
the relay valve to another valve that is connected to
starting motor solenoid (3).
When the normally closed starting motor solenoid
is activated for start-up, the solenoid opens the
connected valve. The valve allows the control air
pressure to flow behind piston (11) inside air starting
motor (5).
Illustration 48
Air starting motor
(6) Air inlet
(7) Vanes
(8) Rotor
(9) Pinion
(10) Reduction gears
(11) Piston
(12) Piston spring
g00563259
The control air pressure pushes the piston. The
piston compresses piston spring (12) and the piston
moves the drive shaft for pinion (9) outward in order
to engage the pinion with the flywheel ring gear. The
starting motor does not crank the engine yet.
After the pinion is engaged with the flywheel ring
gear, a port in the starting motor is opened in order to
allow the control air pressure to flow through hose (4)
to the top of relay valve (1). The relay valve opens in
order to allow the main supply of pressurized air to
flow through the starting motor’s air inlet (6).
48
Systems Operation Section
The pressurized air causes vanes (7) and rotor (8) to
rotate. The rotor uses reduction gears (10) to rotate
the drive shaft for the pinion and the pinion rotates
the flywheel in order to crank the engine.
When the engine starts to run, the flywheel will begin
to rotate faster than the pinion. The design of the
drive shaft for the pinion allows the pinion to move
away from the flywheel. This prevents damage to the
air starting motor, to the pinion, and to the flywheel
ring gear.
When the engine control senses the crank terminate
speed, starting motor solenoid (3) is de-energized.
The solenoid closes the attached valve and the
control air pressure is removed from piston (11).
Piston spring (12) retracts the piston, the drive shaft,
and pinion (9).
The retraction of piston (11) closes the passage for
the control air pressure to relay valve (1). The relay
valve closes in order to shut off the main supply of
pressurized air to the starting motor.
49
Systems Operation Section
Electrical System
i01961883
Electric Starting System
SMCS Code: 1400; 1450
S/N: CWY1-Up
S/N: TJB1-Up; RWA1-Up
S/N: B9P1-Up; GHC1-Up
S/N: CWW1-Up; GHE1-Up
S/N: SXY1-Up; GHM1-Up
S/N: SLY1-Up; GHP1-Up
S/N: TJC1-Up; DKR1-Up
S/N: HAL1-Up; GHR1-Up
g01019316
Illustration 49
Components for the electrical starting system
(1) Terminal box
(2) Magnetic switches
(3) Circuit breaker for the start command
from the Electronic Control Module
(ECM)
When the ECM in terminal box (1) receives an input
for start-up, the ECM supplies +Battery voltage to two
magnetic switches (2). The magnetic switches are
located in a junction box on the side of the engine.
The start command from the ECM is protected by
circuit breaker (3).
(4) Starting motor solenoid
(5) Starting motor
The two magnetic switches are connected in a
secondary electrical circuit to two starting motor
solenoids (4). The start command closes the contacts
of the magnetic switches in order to complete the
secondary electrical circuit. This energizes the
starting motor solenoids.
50
Systems Operation Section
The energizing of the starting motor solenoids
causes the starting motors’ pinions to engage with
the flywheel ring gear.
The starting motor solenoids are also connected
in another electrical circuit between the starting
motors and a source of +24 VDC for cranking the
starting motors. After the starting motor’s pinions
are engaged with the flywheel ring gear, the starting
motor solenoids’ contacts complete the other
electrical circuit for cranking of the starting motors.
The starting motors crank the engine until the ECM
detects the crank terminate speed. Then, the ECM
removes the +Battery voltage from the magnetic
switches. The contacts of the magnetic switches
open and the +Battery voltage is removed from
the starting motor solenoids. The starting motor
solenoids’ contacts open and the +24 VDC for
cranking is removed from the starting motors. The
starting motors’ pinions are disengaged from the
flywheel ring gear.
Illustration 50 is a schematic of the electrical starting
circuit.
51
Systems Operation Section
g01019317
Illustration 50
Schematic for the electrical starting circuit
i01853981
i01566987
Power Supply
Grounding Practices
SMCS Code: 1400
SMCS Code: 1400
Requirements for the Control
System
Proper grounding is necessary for optimum engine
performance and reliability. Improper grounding will
result in uncontrolled electrical circuit paths and in
unreliable electrical circuit paths.
The engine control system requires a clean 24 VDC
power supply that is capable of supplying 30 amperes
of continuous power.
The maximum allowable AC ripple is 150 millivolts AC
peak to peak. For the wiring, the maximum allowable
voltage drop is 1 VDC from the power supply to
the master Electronic Control Module (ECM) in the
engine mounted terminal box.
The power supply for the engine control system must
be separate from the power supply for the starting
motor.
Uncontrolled electrical circuit paths can result in
damage to main bearings, to crankshaft bearing
journal surfaces, and to aluminum components.
Uncontrolled electrical circuit paths can also cause
electrical activity that may degrade the engine
electronics and communications.
Ensure that all grounds are secure and free of
corrosion.
The engine alternator must be grounded to the
negative “-” battery terminal with a wire that is
adequate to carry the full charging current of the
alternator.
52
Systems Operation Section
For the starting motor, do not attach the battery
negative terminal to the engine block.
NOTICE
This engine is equipped with a 24 volt starting system.
Use only equal voltage for boost starting. The use of
a welder or higher voltage will damage the electrical
system.
Ground the engine block with a ground strap that is
furnished by the customer. Connect this ground strap
to the ground plane.
Use a separate ground strap to ground the negative
“-” battery terminal for the control system to the
ground plane.
Disconnect the power when you are working on the
engine’s electronics.
If rubber couplings are used to connect the steel
piping of the cooling system and the radiator,
the piping and the radiator can be electrically
isolated. Ensure that the piping and the radiator are
continuously grounded to the engine. Use ground
straps that bypass the rubber couplings.
Illustration 51
g00285111
Alternator components (typical example)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
Regulator
Roller bearing
Stator winding
Ball bearing
Rectifier bridge
Field winding
Rotor assembly
Fan
The alternator is driven by a belt from an auxiliary
drive at the front right corner of the engine. This
alternator is a three-phase, self-rectifying charging
unit, and regulator (1) is part of the alternator.
i01394904
Alternator
SMCS Code: 1405
NOTICE
Never operate the alternator without the battery in the
circuit. Making or breaking an alternator connection
with heavy load on the circuit can cause damage to
the regulator.
This alternator design has no need for slip rings or
brushes, and the only part that has movement is
rotor assembly (7). All conductors that carry current
are stationary. The conductors are field winding (6),
stator windings (3), six rectifying diodes, and the
regulator circuit components.
Rotor assembly (7) has many magnetic poles. Air
space is between the opposite poles.
The poles have residual magnetism that produces a
small amount of magnetic lines of force between the
poles. As rotor assembly (7) begins to turn between
field windings (6) and stator windings (3), a small
amount of alternating current (AC) is produced in
stator windings (3). This current is from the small,
magnetic lines of force that are made by the residual
magnetism of the poles. This alternating current (AC)
is changed to a direct current (DC). The change
occurs when the current passes through the diodes of
rectifier bridge (5). Most of this current completes two
functions. The functions are charging the battery and
supplying the low amperage circuit. The remainder
of the current is sent to field windings (6). The DC
current flow through field windings (6) (wires around
an iron core) now increases the strength of the
magnetic lines of force. These stronger lines of force
increase the amount of AC current that is produced
in stator windings (3). The increased speed of rotor
assembly (7) also increases the current and voltage
output of the alternator.
53
Systems Operation Section
Voltage regulator (1) is a solid-state, electronic
switch. The regulator feels the voltage in the system.
The regulator will start and the regulator will stop
many times in one second in order to control the field
current to the alternator. The output voltage from the
alternator will now supply the needs of the battery
and the other components in the electrical system.
No adjustment can be made in order to change the
rate of charge on these alternator regulators.
i01394925
Starting Solenoid
SMCS Code: 1467
A solenoid is an electromagnetic switch that does
two basic operations.
When two sets of windings in the solenoid are used,
the windings are called the hold-in windings and the
pull-in windings. Both of the windings have the same
number of turns around the cylinder. However, the
pull-in winding uses a wire with a larger diameter in
order to produce a greater magnetic field. When the
start switch is closed, part of the current flows from
the battery through the hold-in windings. The rest
of the current flows through the pull-in windings to
the motor terminal. The current then goes through
the motor to the ground. When the solenoid is fully
activated, current is shut off through the pull-in
windings. Only the smaller hold-in windings are in
operation for the extended period of time. This period
of time is the amount of time that is needed for
the engine to start. The solenoid will now take less
current from the battery. The heat that is made by the
solenoid will be kept at an acceptable level.
• The solenoid closes the high current starting motor
circuit with a low current start switch circuit.
• The solenoid engages the starter motor pinion with
the ring gear.
i01394933
Starting Motor
SMCS Code: 1451
The starting motor is used to turn the engine flywheel
in order to start the engine.
Illustration 52
g00285112
Typical solenoid schematic
The solenoid has windings (one or two sets) around
a hollow cylinder. The cylinder contains a spring
loaded plunger. The plunger can move forward and
backward. When the start switch is closed and the
electricity is sent through the windings, a magnetic
field is made. The magnetic field pulls the plunger
forward in the cylinder. This moves the shift lever in
order to engage the pinion drive gear with the ring
gear. The front end of the plunger makes contact
across the battery and the motor terminals of the
solenoid. The starting motor begins to turn the
flywheel of the engine.
When the start switch is opened, current no longer
flows through the windings. The spring pushes the
plunger back to the original position. The spring
simultaneously moves the pinion gear away from the
flywheel.
Illustration 53
Cross section of the starting motor (typical example)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Field winding
Solenoid
Clutch
Pinion
Commutator
Brush assembly
Armature
g00285113
54
Systems Operation Section
The starting motor has a solenoid (2). When the start
switch is activated, electricity will flow through the
windings of the solenoid. The solenoid core will move
in order to push pinion (4) with a mechanical linkage.
This will engage with the ring gear on the flywheel of
the engine. Pinion (4) will engage with the ring gear
before the electric contacts in solenoid (2) close the
circuit between the battery and the starting motor.
When the circuit between the battery and the starting
motor is complete, pinion (4) will turn the engine
flywheel. A clutch gives protection to the starting
motor. The engine can not turn the starting motor too
fast. When the start switch is released, pinion (4) will
move away from the flywheel ring gear.
Starting Motor Protection
The starting motor is protected from damage in two
ways:
• The starting motor is protected from engagement
with the engine when the engine is running. The
control feature will not allow the starting motor to
engage if the speed is above 0 rpm.
• The starting motor is protected from continuous
starting. For example, if an operator is holding the
key in the Start position after the engine starts, the
starting motor solenoid will disengage after engine
speed reaches 300 rpm.
i01847547
Circuit Breaker
SMCS Code: 1420
The circuit breaker is a sealed electromagnetic switch
that opens the electrical circuit if the current exceeds
the rating of the circuit breaker.
The circuit breaker has a coil that operates as an
electromagnet. As the current that flows through
the coil increases, the coil’s magnetic field becomes
stronger. If the current exceeds the trip point, the
mechanism that normally closes the electrical circuit
is pulled toward the coil’s magnetic field and the
electrical circuit is opened.
NOTICE
Find and correct the problem that causes the circuit
breaker to open. This will help prevent damage to the
circuit components from too much current.
The circuit breaker is designed to operate in a
temperature range of −40 to 85 °C (−40 to 185 °F).
Because the circuit breaker uses an electromagnet
rather than a metal element that responds to heat,
the circuit breaker is not affected by changes in
the ambient temperature. Also, the electromagnet
operates faster than a metal element.
The circuit breaker is reset with a toggle switch. If
the current continues to exceed the circuit breaker’s
rating, the electrical circuit will remain open even
when the toggle switch is held in the ON position.
The junction box has four circuit breakers that are
identified in Illustration 54.
55
Systems Operation Section
g00927512
Illustration 54
The junction box is located on left side of the engine.
(1) Junction box
(2) 2.5 amp circuit breaker for the engine
control
(3) 10 amp circuit breaker for the customer
(4) 35 amp circuit breaker for the engine
(5) 2.5 amp circuit breaker for the start
command from the master ECM
(6) Positive terminal for the connection of
the engine’s power supply
(7) Negative terminal for the connection of
the engine’s power supply
56
Testing and Adjusting Section
Testing and Adjusting
Section
Electronic Control System
Connecting the Caterpillar
Electronic Technician (Cat ET)
to the Electronic Control Module
(ECM)
Table 5
Tools Needed
i01944371
General Information
(Electronic Control System)
SMCS Code: 1901
Certain programmable parameters must be entered
in order for the electronic control system to operate
properly. Other programmable parameters are
adjusted according to the customer’s preferences
for the installation.
Caterpillar Electronic Service Tools are designed to
help the service technician perform the following
functions:
• Obtain data.
• Diagnose problems.
• Read parameters.
• Program parameters.
• Calibrate sensors.
The tools that are listed in Table 5 are required in
order to enable a service technician to perform the
procedures.
Qty
Personal Computer
1
Single user license for Cat ET
Use the most recent version of this software.
“JERD2124”
1
Software
Data subscription for all engines
“JERD2129”
1
171-4400 Communication Adapter Gp (1)
1
7X-1414 Adapter Cable
1
237-7547 Adapter Cable As
1
(1)
The 7X-1700 Communication Adapter Gp may also be used.
For more information regarding the use of Cat
ET and the PC requirements for Cat ET, refer to
the documentation that accompanies your Cat ET
software.
The engine’s power supply provides the
communication adapter with 24 VDC. Use the
following procedure to connect Cat ET and the
communication adapter to the engine.
1. Turn the engine control switch to the OFF/RESET
position.
57
Testing and Adjusting Section
7. Turn the engine control switch to the STOP
position. The engine should be OFF.
If Cat ET and the communication adapter
do not communicate with the ECM, refer to
Troubleshooting, “Electronic Service Tool Will Not
Communicate With ECM”.
If Cat ET displays “Duplicate Type on data link.
Unable to Service”, check the harness code for
the slave ECM.
The harness inside the terminal box for the slave
ECM has a jumper wire (harness code) that
connects terminals J3-29 and J3-60. The ECM
that is connected to the harness reads the harness
code. This allows the ECM to operate as the slave
ECM. The jumper wire must be connected in order
for the Cat ET to communicate with the modules.
The jumper wire must be connected in order for
the engine to crank. The jumper wire must remain
connected in order for the engine to run.
Check the continuity between terminals J3-29
and J3-60. Verify that the jumper wire is in good
condition. Make repairs, as needed.
Recommendations for
Programming the System
Configuration Parameters
Illustration 55
(1)
(2)
(3)
(4)
(5)
g00927657
PC
196-0055 Serial Cable
171-4401 Communication Adapter II
207-6845 Adapter Cable
7X-1414 Data Link Cable
Note: Items (2), (3), and (4) are part of the 171-4400
Communication Adapter Gp.
2. Connect cable (2) to the RS232 serial port of PC
(1).
Note: If your PC is not equipped with a serial port,
use the 237-7547 Adapter Cable As in order to
connect to the USB port. Connect one end of the
adapter to the end of cable (2). Connect the other
end of the adapter to a USB port on the PC.
3. Connect cable (2) to communication adapter (3).
4. Connect cable (4) to communication adapter (3).
5. Connect cable (4) to cable (5).
6. Connect cable (5) to the service tool connector of
the terminal box.
For descriptions of the parameters, refer to Systems
Operation, “Electronic Control System Parameters”.
The values of the parameters can be viewed on the
“Configuration” screen of Cat ET.
Programmable parameters enable the engine to be
configured in order to meet the requirements of the
application. The system configuration parameters
must be programmed when the application is
installed. Perform this programming before the initial
engine start-up.
Data from a gas analysis is required in order to
determine the correct settings for the air/fuel ratio
control. The data must be entered into Caterpillar
Software, LEKQ6378, “Methane Number Program”.
Incorrect programming of parameters may lead to
complaints about performance and/or to engine
damage.
If an ECM is replaced, the appropriate parameters
must be copied from the original ECM. This can be
done with the “Copy Configuration” feature of Cat ET.
Alternatively, the settings can be recorded on paper
and then programmed into the new module.
58
Testing and Adjusting Section
NOTICE
Changing the parameters during engine operation can
cause the engine to operate erratically. This can cause
engine damage.
Only change the settings of the parameters when the
engine is STOPPED.
Changing the Settings of the
Monitoring System
For descriptions of the monitoring system parameters,
refer to Systems Operation, “Engine Monitoring
System”.
To change the settings of the parameters, use Cat ET
and select the “Service/Monitoring System” screen.
Use care when you program the trip points and the
delay times. Ensure that the response of the ECM is
correct for the application. The monitoring system will
accept any settings within the ranges.
NOTICE
Changing the parameters during engine operation can
cause the engine to operate erratically. This can cause
engine damage.
Only change the settings of the parameters when the
engine is STOPPED.
i01973963
Engine Governing - Adjust
SMCS Code: 1901-025
The response of the throttle actuator can be adjusted
with the Caterpillar Electronic Technician (Cat ET).
Use Cat ET to change these three parameters:
• Proportional Gain
• Integral Gain
• Derivative Gain
The default values should be sufficient for initial
start-up. However, the values may not provide
optimum performance.
These adjustments are provided in order to obtain
optimum responses to changes in the load and in the
speed. The adjustments also provide stability during
steady state operation.
If you have a problem with instability, always
investigate other causes before you adjust the
governor. For example, diagnostic codes and
unstable gas pressure can cause instability.
When you adjust the primary governor, make sure
that the “Grid Status” parameter is “Off”. When you
adjust the auxiliary governor, make sure that the
“Grid Status” parameter is “On”.
To change the proportional gain, the integral gain, or
the derivative gain, use the “Real Time Graphing”
feature on the “Information” drop-down menu of
Cat ET. The graph provides the best method for
observing the effects of your adjustments.
For details on these parameters, refer to Systems
Operation/Testing and Adjusting, “Electronic Control
System Parameters”.
After you make adjustments, always test the stability
by interrupting the engine speed and/or load. Operate
the engine through the entire range of speeds and of
loads in order to ensure stability.
Note: Adjustment of the proportional gain directly
affects the speed of the throttle actuator when there
is a difference between the actual engine speed and
the desired engine speed. An excessive increase of
the proportional gain may amplify instability.
To set the proportional gain, increase the proportional
gain until the actuator becomes unstable. Slowly
reduce the proportional gain in order to stabilize the
actuator. Observe that the engine operates properly
with little overshoot or undershoot.
The adjustment of integral gain dampens the
actuator’s response to changes in load and in speed.
Increasing the integral gain provides less damping.
Decreasing the integral gain provides more damping.
To reduce overshoot, decrease the integral gain. To
reduce undershoot, increase the integral gain.
Note: An increase of the integral gain may require a
decrease of the proportional gain in order to maintain
a stable operation.
Illustration 56 shows some typical curves for transient
responses.
59
Testing and Adjusting Section
g01017541
Illustration 57
The increased width of the line for the actuator voltage indicates
that the throttle actuator is more active as the derivative gain
increases.
(Y) Actuator voltage
(X) Time in seconds
Governor Type
Use Cat ET to select the “Governor Type Setting”
configuration parameter.
For generator set applications, there are two sets of
responses for the throttle actuator. The “Isochronous
Mode” is used to provide “off grid” engine stability
for synchronization. The “Droop Operation” is for
“on grid” stability. Adjustment to the settings for the
throttle actuator relates to both of the responses.
Illustration 56
g01017530
(Y) Engine speed
(X) Time
(1) The proportional gain is too high and the integral gain is too
low. There is a large overshoot on start-up and there are
secondary overshoots on transient loads.
(2) The proportional gain is slightly high and the integral gain is
slightly low. There is a slight overshoot on start-up but the
response to transient loads is optimum.
(3) The proportional gain is slightly low and the integral gain is
slightly high. There is optimum performance on start-up but
slow response for transient loads.
(4) The proportional gain is too low and the integral gain is too
high. The response for transient loads is too slow.
(5) The response to transient loads is adjusted for optimum
performance.
Decrease the derivative gain until a slow, periodic
instability is observed. Then, slightly increase the
derivative gain. Repeat the adjustments of the
proportional gain and of the integral gain. Continue
to increase the derivative gain and readjust the
proportional gain and the integral gain until stability
is achieved and the engine’s response to changes in
load and in speed is optimized.
Illustration 57 is a graphic representation of adjusting
the derivative gain.
i01821257
Manifold Air Pressure Sensor
SMCS Code: 1917
Table 6
Tools Needed
1U-5470 Engine Pressure Group
Quantity
1
Absolute pressure – Absolute pressure is the
gauge pressure plus the local barometric pressure.
Gauge pressure – Gauge pressure is the absolute
pressure minus the local barometric pressure.
The inlet manifold pressure sensor measures the
absolute inlet manifold air pressure.
To verify that the inlet manifold pressure sensor is
accurate, use the Caterpillar Electronic Technician
(ET) to read the inlet manifold air pressure when the
engine is stopped. The correct pressure will be the
ambient barometric pressure.
Use the following procedure to compare the reading
from the inlet manifold pressure sensor with a reading
from the 1U-5470 Engine Pressure Group.
60
Testing and Adjusting Section
To avoid detecting vibrations that are not related to
detonation, the Electronic Control Module (ECM)
only monitors a detonation sensor when one of the
sensor’s cylinders is between 5 degrees after top
center and 40 degrees after top center. Therefore,
the “Block Tap” method of testing the detonation
sensors does not work for the G3500C Engines.
For information on testing the detonation sensors,
refer to the engine’s Troubleshooting manual.
i01903257
Engine Speed/Timing Sensor
Illustration 58
g00929850
SMCS Code: 1912
Right view at the rear of the engine
Plugs in the air inlet manifold
Remove one of the plugs from the air inlet manifold.
Connect a line from the opening to a pressure gauge
from the 1U-5470 Engine Pressure Group. Operate
the engine under a load. Use Cat ET to read the inlet
manifold air pressure. Read the pressure gauge from
the 1U-5470 Engine Pressure Group and add the
local barometric pressure to the reading. Compare
the calculation to the reading from Cat ET.
If a diagnostic code is generated for the engine
speed/timing sensor, refer to the Troubleshooting
manual.
For proper operation, the condition and installation of
the sensor must be correct. If the condition or the
installation of the sensor is suspect, use the following
procedure.
i01956566
Detonation Sensor
SMCS Code: 1559
Detonation is engine knock that occurs after
combustion has occurred. The excessive mechanical
stress and thermal stress can reduce the service life
of the engine. There are several possible causes
of detonation. Examples are a rich air/fuel mixture,
overload, a high compression ratio, and high inlet
manifold air temperature.
Combustion of the air/fuel mixture prior to the spark is
a premature ignition. This is usually caused by a hot
spot in the combustion chamber. Possible sources of
premature ignition are an incorrect spark plug, an
incorrectly installed spark plug, and deposits in the
combustion chamber. Detonation can be the result of
premature ignition. The premature ignition has the
effect of advanced ignition timing.
Illustration 59
g00760464
(1) Engine speed/timing sensor
1. Remove engine speed/timing sensor (1). Inspect
the condition of the end of the magnet. Look for
wear and contaminants.
2. Clean any debris from the face of the magnet.
Although a sensor may indicate the presence of
detonation, the problem could be a premature
ignition. An indication of detonation can also be
caused by excessive mechanical engine noise.
Illustration 60
(2) Sliphead
g00909543
61
Testing and Adjusting Section
3. Check the tension of sliphead (2). Gently extend
the sliphead for a minimum of 4 mm (0.16 inch).
Then push back the sliphead.
When the sliphead has the correct tension, at
least 22 N (5 lb) of force is required to push in the
sliphead from the extended position.
NOTICE
The sliphead must be fully extended when the speed/
timing sensor is installed so that the sensor maintains
the correct clearance with the speed-timing wheel.
If the correct clearance is not maintained, the signal
from the sensor will not be generated.
Do not install the sensor between the teeth of the
speed-timing wheel. Damage to the sensor would result. Before installing the sensor, ensure that a tooth
of the wheel is visible in the mounting hole for the sensor.
i01821485
Ignition Transformer
SMCS Code: 1561
If an ignition transformer is suspect, use the following
procedure to check the transformer:
Ignition systems can cause electrical shocks.
Avoid contacting the ignition system components
and wiring.
Do not attempt to remove the transformers when
the engine is operating. The transformers are
grounded to the valve covers. Personal injury or
death may result and the ignition system will be
damaged if the transformers are removed during
engine operation.
4. Install the engine speed/timing sensor.
a. Ensure that a tooth on the speed-timing wheel
is visible in the mounting hole for the sensor.
1. Turn the engine control OFF. Switch the engine’s
circuit breaker OFF.
b. Extend sliphead (2) by a minimum of 4 mm
(0.16 inch).
c. Coat the threads of the sensor with 4C-5598
High Temperature Anti-Seize.
Note: The sliphead is designed to contact a tooth
of the speed-timing wheel. The maximum allowable
gap between the sliphead and the tooth is 0.5 mm
(0.02 inch).
d. Install the sensor. Tighten the locknut to
40 ± 5 N·m (30 ± 4 lb ft).
Timing Calibration
Calibration of the timing is required only after the
following circumstances:
• The master ECM has been replaced.
• The speed/timing sensor has been replaced.
• The speed-timing wheel and/or the rear gear train
have been adjusted.
• The speed-timing wheel and/or the rear gear train
have been replaced.
The Caterpillar Electronic Technician (Cat ET) uses
the engine speed/timing sensor to help calibrate
the engine timing. For instructions on the timing
calibration, refer to Troubleshooting, “Engine
Speed/Timing Sensor - Calibrate”.
Illustration 61
(1)
(2)
(3)
(4)
(5)
(6)
g00929956
Cover
Connector
Transformer
Extension
Spark plug
Mounting flange for the transformer
2. Remove cover (1).
3. Disconnect the ignition harness from connector
(2). Remove transformer (3) and extension (4)
from the engine.
4. Inspect the body of transformer (3) and extension
(4) for corrosion and/or for damage.
62
Testing and Adjusting Section
5. The extension has an internal O-ring seal for
spark plug (5). Inspect the O-ring seal for damage.
6. The extension has an internal terminal for the
spark plug. Inspect the terminal for looseness,
for corrosion, and/or for damage. Insert an extra
spark plug into the transformer and check the
terminal for spring pressure.
Note: The resistance of the secondary coil will vary
with the temperature. Illustration 64 demonstrates the
relationship between the secondary coil’s resistance
and the temperature. A reading that is within ± 1000
ohms is acceptable. For example, if the transformer’s
temperature is 60 °C (140 °F), the correct resistance
is 22,000 ± 1000 ohms.
NOTICE
The extension can be scratched and damaged with a
wire brush. Do not use a wire brush on the extension.
7. Clean any deposits from the inside of the
extension. Use a 6V-7093 Brush with isopropyl
alcohol.
Illustration 62
g00754013
Illustration 64
Symbol for a diode
g00863850
Resistance versus temperature
8. Measure the primary circuit by checking the
voltage of the diode.
(Y) Resistance in ohms
(X) Temperature in degrees Celsius (degree Fahrenheit)
9. Measure the resistance of the secondary circuit.
a. Set the multimeter to the 40,000 Ohm
scale. Measure the resistance between the
extension’s internal terminal for the spark plug
and mounting flange (6) for the transformer.
Illustration 63
g00829100
Transformer’s connector for the ignition harness
(A) Terminal
(B) Terminal
(C) Unused
If the resistance between the terminal for the
spark plug and the mounting flange for the
transformer is within the acceptable tolerance,
proceed to Step 10.
Resistance that is significantly outside of
this range could indicate a problem with the
transformer or with the extension.
a. Set the multimeter to the diode scale. Connect
the multimeter’s leads to terminals (A) and
(B) on the transformer’s connector for the
ignition harness. The polarity of the leads does
not matter. Measure the voltage between the
terminals and record the measurement.
10. Switch the suspect transformer with a transformer
from a different cylinder that is known to be good.
Install the transformers.
b. Reverse the polarity of the probe and measure
the voltage between the terminals again.
11. Reset the control system. Clear any logged
diagnostic codes.
One of the measurements is approximately 0.4
to 0.6 VDC. The other measurement indicates
an open circuit.
Voltage that is significantly outside of this range
could indicate a problem with the transformer.
12. Start the engine and operate the engine in order
to generate a diagnostic code.
If the problem follows the transformer, replace the
transformer. Make sure that you use the correct
transformer for the engine. Reset the control
system. Clear any logged diagnostic codes.
If the problem stays with the cylinder, there is a
problem with the spark plug or with the electrical
circuit for the transformer.
63
Testing and Adjusting Section
For instructions on the electrical circuit, refer to
the engine’s Troubleshooting manual.
Spark Plug
If a diagnostic code is generated for the ignition
transformer’s secondary circuit, the spark plug may
need to be replaced. Misfire and a cold cylinder
are other indications of a worn spark plug. Use the
Caterpillar Electronic Technician (ET) to monitor the
exhaust port temperatures in order to locate a cold
cylinder.
For instructions on inspection and replacement of
the spark plug, refer to the engine’s Operation and
Maintenance Manual.
Illustration 65
g00837850
Spark plug’s precombustion chamber
There is virtually no maintenance for the spark plug.
The electrode gap is not adjustable. The resistance
cannot be measured. Unless the holes in the spark
plug’s precombustion chamber become plugged, no
cleaning is required.
64
Testing and Adjusting Section
Fuel System
For information on acceptable fuels for the engine,
refer to the engine’s Operation and Maintenance
Manual.
i01821544
General Information (Fuel
System)
Air/Fuel Ratio Control - Adjust
SMCS Code: 1250
SMCS Code: 1266-025
The High Heat Value (HHV) is a measurement of
the total heat that is generated by combustion of
a fuel. When any hydrocarbon is used as a fuel in
an internal combustion engine, water is one of the
products of combustion. The water is converted into
steam before leaving the engine. The conversion
requires heat. The steam removes the heat and the
energy is not used by the engine. The HHV minus
the heat that is used to vaporize the water equals the
Low Heat Value (LHV) of the fuel.
The air/fuel ratio must be adjusted properly in order
to comply with the emissions requirements of the site.
The correct air/fuel ratio also helps ensure stable
operation. To adjust the air/fuel ratio, perform the
following procedure.
The fuel must be mixed with air in order to produce
combustion. The amount of air that is required for
efficient combustion will vary for different types of
fuels because of the fuels’ different compositions.
For optimum engine operation, the air/fuel ratio must
be adjusted properly.
The fuel’s methane number indicates the tendency of
the fuel to detonate. Fuel with a low methane number
burns more quickly than fuel with a high methane
number. Additionally, the heat that is produced by
compression can ignite fuel with a low methane
number sooner than fuel with a high methane
number. If an engine is using low methane fuel and
the timing is too early, detonation will occur. To avoid
detonation, the engine timing must be retarded for
low methane. The engine may also need a lower
compression ratio.
An engine with a low compression ratio is able to
utilize fuels with low methane. An engine with a high
compression ratio can use a more limited range of
fuels. However, a higher power output and greater
fuel economy can be obtained. Operation without
combustion problems and production of the required
power from the available fuel depends on the correct
engine configuration.
For a detailed explanation of methane numbers,
see Application and Installation Guide, LEKQ7256,
“Fuels/Fuel Systems”.
Follow the guide for fuel usage that is in the engine’s
Engine Performance publication. These publications
are available from your Caterpillar dealer.
For detailed information on gaseous fuels, refer to
Engine Data Sheet, LEKQ3105, “Internal Combustion
Engine Fuel Gases”.
i01955925
1. Connect a properly calibrated emissions analyzer
to the exhaust stack.
2. Connect the Caterpillar Electronic Technician
(Cat ET) to the service tool connector. Refer
to Systems Operation/Testing and Adjusting,
“General Information (Electronic Control System)”.
3. Verify that the “Fuel Quality” and “Gas Specific
Gravity” parameters are programmed correctly.
Use the values that are obtained from the
Caterpillar Software, LEKQ6378, “Methane
Number Program”.
4. Verify that the value for the “Fuel Specific Heat
Ratio” parameter is correct. Enter a value of 1.4
for processed, dry pipeline natural gas.
5. Start the engine. Increase the engine speed to
high idle rpm. Verify that the engine is stable.
If the engine is unstable, perform the following
procedure.
a. Record the values for these parameters:
• “Governor Proportional Gain”
• “Governor Integral Gain”
• “Governor Derivative Gain”
b. Set the values for the “Governor Proportional
Gain”, “Governor Integral Gain”, and “Governor
Derivative Gain” parameters to zero.
c. Adjust the “Fuel Quality” parameter until the
engine becomes stable and the exhaust
oxygen is approximately four percent. Verify
that the exhaust port temperatures are below
the setpoint for a warning.
65
Testing and Adjusting Section
d. Adjust the primary governor. Refer to Systems
Operation/Testing and Adjusting, “Engine
Governing - Adjust”.
6. Close the main circuit breaker for the generator in
order to engage the generator.
Note: When the engine load becomes greater than
25 percent, the air/fuel ratio control will operate in
the feedback mode.
7. Slowly ramp the load up to 30 percent.
Note: When the air/fuel ratio control is in the
feedback mode, the Fuel Correction Factor (FCF)
may no longer be 100 percent. The Electronic Control
Module may adjust the FCF in order to compensate
for the fuel quality and for the ambient conditions.
8. Set the “Desired Emission Gain Adjustment”
parameter to a value of “100”.
9. Verify that the reading on Cat ET for the
generator’s power output agrees with the
switchgear’s reading.
If the readings do not agree, adjust the “Generator
Output Power Sensor Scale Factor” and/or
the “Generator Output Power Sensor Offset”
parameters. Also, make sure that the “Engine
Output Power Configuration” and the “Engine
Driven Accessory Load Configuration” parameters
are accurately programmed. Refer to Systems
Operation/Testing and Adjusting, “Electronic
Control System Parameters”.
A small change in the “Desired Emission Gain
Adjustment” causes a large change in the actual
exhaust emissions. For example, an adjustment of
one percent in the parameter’s value will result in a
change of 20 to 40 ppm in the actual level of NOx.
When you adjust the exhaust emissions, make a
small change in the value of the gain. Wait until
the system stabilizes. Check the emissions again.
Repeat the process until the desired emissions
level is achieved.
Use the emissions analyzer in order to verify that
the values of emissions meet the requirements
of the site.
i01818876
Finding the Top Center
Position for the No. 1 Piston
SMCS Code: 1105-531
Table 7
Tools Needed
9S-9082 Engine Turning Tool
Quantity
1
10. Slowly ramp up to 70 percent load. Verify that the
engine is stable.
If the engine is unstable, adjust the auxiliary
governor. Refer to Systems Operation/Testing and
Adjusting, “Engine Governing - Adjust”.
11. Verify that the NOx emissions are above the
desired full load setting.
Illustration 66
g00284799
Timing bolt location (typical example)
12. Slowly ramp up to 100 percent load.
(1) Cover
(2) Timing bolt
(3) Plug
13. Verify that the reading on Cat ET for the
generator’s power output agrees with the
switchgear’s reading.
1. Remove cover (1) and plug (3) from the right front
side of the flywheel housing.
14. Adjust the “Desired Emission Gain Adjustment”
parameter in order to obtain the values of
emissions that are required at the site.
• To lean the air/fuel mixture, decrease the gain
adjustment.
• To richen the air/fuel mixture, increase the gain
adjustment.
66
Testing and Adjusting Section
i01821606
Camshaft Timing
SMCS Code: 1210
Timing Check
Table 8
Tools Needed
9S-9082 Engine Turning Tool
Illustration 67
Quantity
1
g00284800
Timing bolt installation (typical example)
(2) Timing bolt
(4) 9S-9082 Engine Turning Tool
2. Put timing bolt (2) through the timing hole in
the flywheel housing. Use the 9S-9082 Engine
Turning Tool (4) and a ratchet wrench with a
1/2 inch drive in order to turn the flywheel in
the direction of normal engine rotation. Turn the
flywheel until the timing bolt engages with the hole
in the flywheel.
Note: If the flywheel is turned beyond the point of
engagement, the flywheel must be turned in the
direction that is opposite of normal engine rotation.
Turn the flywheel by approximately 30 degrees.
Then turn the flywheel in the direction of normal
engine rotation until the timing bolt engages with the
threaded hole. This procedure will remove the play
from the gears when the No. 1 piston is on the top
center.
3. Remove the valve cover for the No. 1 cylinder
head.
4. The inlet and exhaust valves for the No. 1 cylinder
are fully closed if the No. 1 piston is on the
compression stroke and the rocker arms can be
moved by hand. If the rocker arms cannot be
moved and the valves are slightly open, the No. 1
piston is on the exhaust stroke. Find the cylinders
that need to be checked or adjusted for the stroke
position of the crankshaft after the timing bolt has
been installed in the flywheel. Refer to Testing
And Adjusting, “Crankshaft Position for Valve
Lash Setting”.
Note: When the actual stroke position is identified
and the other stroke position is needed, remove the
timing bolt from the flywheel. Turn the flywheel by 360
degrees in the direction of normal engine rotation.
Illustration 68
g00284801
Location of timing pins (typical example)
(1) Timing hole
(2) Timing pin
1. Remove rear camshaft covers from both sides of
the engine.
2. Refer to Testing and Adjusting, “Finding the Top
Center Position for the No. 1 Piston”.
Note: When the timing bolt is installed in the flywheel,
it is not necessary to remove the No. 1 valve cover
in order to find the compression stroke. Both rear
camshaft covers must be removed in order to check
the timing.
3. When the timing bolt is installed in the flywheel,
look at the rear end of the camshaft. If the timing
ring is visible, then the No. 1 piston is on the
compression stroke. If the timing ring is not visible,
feel the back of the camshaft for the groove. If the
groove is at the back of the camshaft, the flywheel
must be turned by 360 degrees in order to put the
No. 1 piston on the compression stroke.
67
Testing and Adjusting Section
After the timing check procedure is completed, the
timing bolt will be engaged in the flywheel with No. 1
piston at the top center (TC) position.
1. Disconnect the ignition harness from all of the
ignition transformers on the side of the engine
with the camshaft that needs adjustment. Remove
the ignition transformers.
g00284802
Illustration 69
Installation of timing pins (typical example)
(2) Timing pin
(3) RH Camshaft
4. When the timing bolt is installed in the flywheel
and the No. 1 piston is on the compression stroke,
remove timing pins (2) from the storage positions.
5. Install timing pins (2) through timing holes (1) in
the engine block. Install timing pins (2) into the
groove in camshaft (3) on each side of the engine.
In order to time the engine correctly, the timing
pins must fit into the groove of each camshaft.
If the timing pins do not engage in the grooves of
both camshafts, the engine is not in time, and one
or both camshafts must be adjusted.
6. Proceed to the “Timing Adjustment” procedure.
NOTICE
If a camshaft is out of time more than 18 degrees
(approximately 1/2 the diameter of timing pin out of
groove), the valves can make contact with the pistons.
This will cause damage that will make engine repair
necessary.
Illustration 70
g00930076
(1) Bolt
(2) Rocker Shaft
2. Remove all valve covers on the side of the engine
with the camshaft that needs adjustment. Loosen
bolts (1) that hold rocker shaft (2) to the valve
cover bases until all rocker arms are free from the
valves.
Note: The above procedure must be done before the
camshaft drive gear is pulled off the camshaft taper.
Timing Adjustment
Table 9
Tools Needed
Quantity
9S-9082 Engine Turning Tool
1
1P-0820 Hydraulic Puller
1
8B-7548 Push-Puller Tool Group
1
8B-7559 Adapter
2
5H-1504 Hard Washer
3
9U-6600 Hand Hydraulic Pump
1
Illustration 71
Left rear
Note: Before any timing adjustments are made,
make sure that adjustments are necessary. Refer to
“Timing Check”.
(3) Cover
(4) Speed/Timing sensor
g00662269
68
Testing and Adjusting Section
3. Remove camshaft gear cover (3) from the rear of
the engine. If the left rear camshaft gear must be
removed, remove speed/timing sensor (4) first.
NOTICE
Do not apply more than 41,340 kPa (6,000 psi) of pressure to 1P-0820 Hydraulic Puller. 8B-7559 Adapters
are rated at 5 ton each and 1P-0820 Hydraulic Puller
is rated at 17 ton at 68,900 kPa (10,000 psi). If too
much pressure is applied, the gear may be damaged.
8. Use the 8B-7559 Adapter and needed parts from
the 8B-7548 Push-Puller Tool Group to install the
1P-0820 Hydraulic Puller on the camshaft drive
gear. Apply 41,340 kPa (6,000 psi) to the puller
and tap the screw until the camshaft drive gear is
free of the camshaft taper. Remove the tooling
and the camshaft drive gear from the camshaft.
Illustration 72
g00662337
Rear gear group
(5) Gear (left camshaft drive)
(6) Idler gear
(7) Speed/Timing ring
(8) Gear (right camshaft drive)
(9) Washer
(10) Bolt
(11) Bolt
(12) Plate
4. To remove the left camshaft drive gear, remove
bolt (10) and washer (9). Remove speed/timing
ring (7) from the left camshaft.
5. To remove right camshaft drive gear, remove bolt
(11) and plate (12) from the right camshaft.
Illustration 74
g00662447
Camshaft timing
(13) Timing pin
9. Remove timing pins (13) from the storage
positions which are located under the rear
camshaft covers on each side of the engine.
10. Turn the camshafts until timing pins (13) can be
installed through timing holes and into the grooves
(slots) in the camshaft.
11. Use the following procedure to install camshaft
gears (5) and (8):
Illustration 73
g00662446
Removing the camshaft drive gear
(A) 1P-0820 Hydraulic Puller
(12) Plate
6. Use tooling (A) to remove camshaft drive gears
(5) and (8).
7. Install the three 5H-1504 Hard Washers behind
plate (12). This plate holds the camshaft drive
gear on the camshaft. Install plate (12) and bolt
(11) on the camshaft.
a. For correct timing, the timing bolt must be
installed in the flywheel and all gear clearance
(backlash) must be removed. Turn the
camshaft drive gears in the same direction as
crankshaft rotation and hold in this position.
b. Pin both camshafts and put the camshaft drive
gears in position in line with idler gears (6) on
each camshaft taper.
Note: Make sure that the gear tapers and the shaft
tapers are clean, dry, and free of lubricants.
69
Testing and Adjusting Section
c. Install speed/timing ring (7), bolt (10) and
washer (9) on the left side. Install bolt (11) and
plate (12) on the right side in order to hold the
camshaft drive gears to each camshaft.
d. Remove camshaft timing pins (13). Tighten
bolts (10) and (11) to a torque of 360 ± 40 N·m
(26 ± 30 lb ft).
e. Strike plate (12) or the center of speed/timing
ring (7). This will seat the gear on the
taper. Then tighten the bolt to a torque of
360 ± 40 N·m (266 ± 30 lb ft).
Note: If necessary, repeat Step 11.e until the torque
does not change. Make sure that the drive gears are
in full contact with the taper on the camshafts.
f. Verify the crankshaft in relation to the camshaft
by installing camshaft timing pins (13). Loosen
bolt (11) and the camshaft drive gear if the
timing pins cannot be installed. Repeat the
installation procedure of the camshaft drive
gear.
12. Install the gasket and the camshaft gear cover on
the rear housing. Use two 3/8 inch by 6 inch long
guide bolts.
13. Remove timing pins (13) from the camshafts.
Install timing pins (13) in the storage positions.
Install the covers over the camshafts and timing
pins.
14. Remove the timing bolt from the flywheel housing.
15. Install the 5M-6213 Pipe Plug in the flywheel
housing timing hole. Remove the engine turning
pinion, and install the cover and the gasket.
16. Correctly engage the rocker arms with the
pushrods. Tighten the bolts for the rocker shafts to
a torque of 120 ± 20 N·m (89 ± 15 lb ft).
17. Adjust the valve lash. Refer to Testing And
Adjusting, “Valve Lash and Valve Bridge
Adjustment”.
70
Testing and Adjusting Section
Air Inlet and Exhaust
System
i02085901
For optimum operation, replace the air filter when
the air filter restriction reaches the restriction value
for your particular engine application. Refer to
the applicable Gas Engine Technical Data Sheet
for additional information. The maximum air filter
restriction is 3.7 kPa (15 inches of H2O).
Restriction of Air Inlet and
Exhaust
Aftercooler Differential Pressure
SMCS Code: 1050-040
Aftercooler differential pressure is the difference in
air pressure between the inlet and the outlet of the
aftercooler.
The efficiency of the engine and the engine power
are reduced if there is restriction in the air inlet and/or
the exhaust system.
Inspect the air inlet and exhaust system. Make sure
that there are no obstructions or leaks in the system.
Table 10
Tools Needed
1U-5470 Engine Pressure Group
Qty
1
Illustration 76
g01052146
(1) Plug
Illustration 75
g00295554
1U-5470 Engine Pressure Group
The 1U-5470 Engine Pressure Group is used to
measure the inlet air restriction and the exhaust back
pressure.
Air Inlet Restriction
Air inlet restriction is the difference in pressure
between the air lines after the air cleaner and the
atmospheric air pressure.
Use the differential pressure gauge of the 1U-5470
Engine Pressure Group in order to measure the air
inlet restriction. Connect the pressure port of the
differential pressure gauge to the opening for the air
filter service indicator on the air cleaner.
The maximum differential pressure for the aftercooler
is 10 kPa (40 inch of H2O).
The 8T-0452 Manometer Gauge is used to measure
the differential pressure across the aftercooler.
Remove plugs (1) from the aftercooler. Connect the
manometer in the location of the plugs. Measure the
differential pressure when the engine is operating
at full load.
Exhaust Restriction
Exhaust restriction (back pressure) is the difference
in the pressure between the exhaust at the outlet
elbow and the atmospheric air pressure.
In addition to the loss of efficiency and power,
excessive exhaust restriction will lead to these
results: high engine temperatures, reduced service
life of the turbocharger, and early problems with inlet
and exhaust valves.
71
Testing and Adjusting Section
Use the differential pressure gauge of the 1U-5470
Engine Pressure Group in order to measure the
exhaust back pressure.
Hot engine components can cause injury from
burns. Before performing maintenance on the
engine, allow the engine and the components to
cool.
Making contact with a running engine can cause
burns from hot parts and can cause injury from
rotating parts.
When working on an engine that is running, avoid
contact with hot parts and rotating parts.
Connect the pressure port of the differential pressure
gauge to the test location on the exhaust manifold.
The test location may be located anywhere along
the exhaust piping after the turbocharger but before
the muffler. Choose a location that is as close to the
engine as possible. Install the probe into a straight
pipe that is three to five diameters of the pipe away
from the last transition.
The maximum exhaust back pressure is 6.7 kPa
(27 inches of H2O). If the exhaust restriction reaches
this limit, determine the cause of the restriction and
correct the condition.
i01821658
Measuring Inlet Manifold
Temperature
g00929850
Illustration 77
Right view at the rear of the engine
Plugs in the air inlet manifold
To measure the inlet manifold air temperature, use
the 4C-6500 Digital Thermometer. Remove one
of the plugs from the air inlet manifold. Insert a
temperature probe in place of the plug. Measure the
temperature when the engine is operating at full load.
If the inlet manifold air temperature is too high,
inspect the thermostatic valve and the separate
circuit’s cooling system.
i01896328
Measuring Exhaust
Temperature
SMCS Code: 1088-082
Table 12
Tools Needed
SMCS Code: 1921-082
Qty
4C-6090 Temperature Selector Group
1
6V-9130 Temperature Adapter
1
237-5130 Digital Multimeter
1
Table 11
Tools Needed
4C-6500 Digital Thermometer
Qty
1
The Electronic Control Module (ECM) uses the inlet
manifold air temperature to help calculate the density
of the air/fuel mixture.
Use the Caterpillar Electronic Technician (ET) to
monitor the inlet manifold air temperature. The
temperature can be verified with the 4C-6500 Digital
Thermometer.
Use the Caterpillar Electronic Technician (ET) to
monitor individual cylinder exhaust temperatures, the
exhaust temperature to the turbocharger, and the
exhaust temperature after the turbocharger.
The temperatures can be verified with the 4C-6090
Temperature Selector Group, with the 6V-9130
Temperature Adapter, and with the 237-5130 Digital
Multimeter. Refer to Operating Manual, NEHS0537
for the complete operating instructions for the
4C-6090 Temperature Selector Group.
72
Testing and Adjusting Section
i01599542
Compression
• Minimize the cranking time. This will enable a
maximum consistent cranking speed for the check.
Also, the battery power will be conserved.
SMCS Code: 1215-081
Table 13
Tools Needed
193-5859
Cylinder Pressure Gauge
Gp (Gas Engine)
• Fully open the throttle plate.
Quantity
Illustration 78 is a graph of typical cylinder pressures
for engines with different compression ratios.
1
Cylinder pressure can be measured during inspection
of the spark plugs. The condition of the following
items can be tested by checking the cylinder
pressure: valves, valve seats, pistons, piston rings,
and cylinder liners.
A loss of cylinder pressure or a change of pressure
in one or more cylinders may indicate the following
conditions. These conditions may indicate a problem
with lubrication:
• Excessive deposits
• Guttering of valves
• A broken valve
• A piston ring that sticks
• A broken piston ring
• Worn piston rings
• Worn cylinder liners
Measure the cylinder pressure of an engine after
approximately 250 hours of operation. Record the
data. Continue to periodically measure the cylinder
pressure. Comparing the recorded data to the new
data provides information about the condition of the
engine.
Note: Cylinder pressure is one of the three factors
that help to determine the in-frame overhaul interval.
Refer to Operation and Maintenance Manual,
“Overhaul (In-Frame)”.
If the cylinder pressure has risen by one or more
compression ratios, the engine needs a top end
overhaul in order to remove deposits. Failure to
remove the deposits will increase the chance for
detonation. Severe guttering of the valves will occur.
To measure the cylinder pressure, use the 193-5859
Cylinder Pressure Gauge Gp (Gas Engine). Use the
Special Instruction, NEHS0798 that is included with
the gauge. Use the following guidelines:
• Remove all of the spark plugs.
Illustration 78
g00828960
(Y) Cylinder pressure in kPa
(X) Compression ratio
(1) Normal range for cylinder pressure
i01821673
Valve Lash and Valve Bridge
Adjustment
SMCS Code: 1102-036
Valve Lash Check
Measure the valve lash between the rocker arm and
the valve bridge. Perform checks and adjustments
with the engine stopped. The valves must be fully
closed. To determine whether the valves are fully
closed, refer to Testing And Adjusting, “Finding the
Top Center Position for the No. 1 Piston” and Testing
And Adjusting, “Crankshaft Position for Valve Lash
Setting”.
73
Testing and Adjusting Section
An adjustment is NOT NECESSARY if the valve lash
is within the tolerance that is listed in Table 14.
Table 14
Valve Lash Check: Engine Stopped
Valves
Acceptable Valve Lash Range
Inlet
0.43 to 0.58 mm (0.017 to 0.023 inch)
Exhaust
1.19 to 1.35 mm (0.047 to 0.053 inch)
If the measurement is not within tolerance, adjust the
valve bridge and then adjust the valve lash.
Valve Bridge Adjustment
The valve bridge must be adjusted before the valve
lash is adjusted. The valve bridge can be adjusted
without removing the rocker arms and shafts. The
valves must be fully closed. To determine whether the
valves are fully closed, refer to Testing And Adjusting,
“Finding the Top Center Position for the No. 1 Piston”
and Testing And Adjusting, “Crankshaft Position for
Valve Lash Setting”.
Note: If the cylinder head is disassembled, keep the
bridges with the respective valves. Check that the
bridge dowels are installed to the correct height.
Lubricate the bridge dowel, the bore for the bridge
dowel, and the top contact surface of the bridge.
Install the bridge on the dowel.
Use the following procedure to adjust the valve
bridges:
Illustration 79
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Cover
Ignition harness
Transformer
Extension
O-ring seal
Valve cover
Seal
1. Remove cover (1).
2. Disconnect ignition harness (2).
g00930185
74
Testing and Adjusting Section
3. Remove transformer (3) and extension (4) as a
unit. Inspect the extension’s internal O-ring seal
for the spark plug and inspect O-ring seal (5). If an
O-ring seal is damaged or deteriorated, obtain a
new O-ring seal for assembly.
4. Remove valve cover (6). Inspect seal (7). If the
seal is damaged or deteriorated, obtain a new
seal for assembly.
13. Install cover (1).
Valve Lash Adjustment
The valve bridge must be adjusted before the valve
lash is adjusted.
Note: You can use the 147-5482 Valve Lash Gauge
Group to measure the valve lash. You will also need
the 147-2056 Dial Indicator or the 147-5537 Dial
Indicator.
1. Ensure that the No. 1 piston is at the top center
(TC) position. Refer to Testing And Adjusting,
“Finding the Top Center Position for the No. 1
Piston”.
2. Work on the appropriate cylinders that are listed
in Testing and Adjusting, “Crankshaft Positions
for Valve Lash Setting”.
3. Before you perform any adjustments, use a soft
hammer to lightly tap each rocker arm at top of the
adjustment screw. This will ensure that the lifter
roller is seated against the camshaft.
Illustration 80
g00930186
(8) Locknut
(9) Adjusting screw
(10) Rocker arm
(11) Valve bridge
5. Loosen locknut (8) and adjusting screw (9).
6. Press straight down on rocker arm (10) at the
contact point for valve bridge (11). Turn adjusting
screw (9) clockwise until the screw just contacts
the valve stem.
7. Tighten adjusting screw (9) for an additional 25 ±
5 degrees in order to straighten the valve bridge
onto the dowel.
8. Hold adjusting screw (9) in position and tighten
locknut (8) to 30 ± 4 N·m (22 ± 3 lb ft).
9. Make sure that the valve lash is correct. Refer to
“Valve Lash Check”.
10. Make sure that seal (7) is in good condition.
Install valve cover (6).
11. Make sure that O-ring seal (5) is in good condition.
Install extension (4) and transformer (3) as a unit.
12. Connect ignition harness (2).
Illustration 81
(1)
(2)
(3)
(4)
g00930187
Locknut
Adjusting screw
Rocker arm
Valve bridge
4. Loosen locknut (1) and adjusting screw (2).
5. Insert the appropriate feeler gauge between
rocker arm (3) and the contact surface of valve
bridge (4). Refer to Table 15.
75
Testing and Adjusting Section
Table 15
Valve Lash Setting: Engine Stopped
Valves
Gauge Dimension
Inlet
0.51 mm (0.020 inch)
Exhaust
1.27 mm (0.050 inch)
6. Hold adjusting screw (2) in place and tighten
locknut (1) to a torque of 70 ± 15 N·m (52 ± 11 lb ft).
7. Verify that the setting is correct.
8. Remove the timing bolt from the flywheel housing.
Rotate the crankshaft for 360 degrees. Install the
timing bolt in the flywheel housing.
9. With the No. 1 piston in the top center of the
opposite stroke, perform Steps 2 through 7 for the
remaining cylinders.
10. Remove the timing bolt from the flywheel housing.
i02079745
Crankshaft Position for Valve
Lash Setting
SMCS Code: 1105; 1202
The SAE standard engine crankshaft rotation is
counterclockwise when the crankshaft is viewed from
the flywheel end.
Table 16
Crankshaft Positions for Valve Lash Setting
Standard Counterclockwise Rotation
Engine
G3516
Stroke for the Number 1
Piston At the Top Center
Position (1)
Inlet Valves
Exhaust Valves
Compression Stroke
1-2-5-7-8-12-13-14
1-2-3-4-5-6-8-9
Exhaust Stroke
3-4-6-9-10-11-15-16
7-10-11-12-13-14-15-16
Firing Order
G3520
Compression Stroke
1-2-5-6-9-10-11-13-14-17-18
1-2-3-4-11-12-13-14-15-16
Exhaust Stroke
3-4-7-8-12-15-16-19-20
5-6-7-8-9-10-17-18-19-20
Firing Order
(1)
1-2-5-6-3-4-9-10-15-16-11-12-13-14-7-8
1-2-11-12-3-4-15-16-7-8-19-20-9-10-17-18-5-6-13-14
Put the No. 1 Piston at the top center (TC) position and identify the correct stroke. Refer to Testing And Adjusting, “Finding the Top Center
Position for the No. 1 Piston”. Find the top center (TC) position for a particular stroke and make the adjustment for the correct cylinders.
Remove the timing bolt. Turn the flywheel by 360 degrees in the direction of normal engine rotation. This will put the No. 1 piston at the top
center (TC) position on the opposite stroke. Install the timing bolt in the flywheel and complete the adjustments for the cylinders that remain.
76
Testing and Adjusting Section
Lubrication System
i01794028
i01574160
General Information
(Lubrication System)
Excessive Engine Oil
Consumption - Inspect
SMCS Code: 1348-040
Engine Oil Leaks on the Outside of
the Engine
SMCS Code: 1300
The following problems generally indicate a problem
in the engine’s lubrication system.
• Excessive consumption of engine oil
• Low engine oil pressure
• High engine oil pressure
• Excessive bearing wear
Check for leakage at the seals at each end of the
crankshaft. Look for leakage at the gasket for the
engine oil pan and all lubrication system connections.
Look for any engine oil that may be leaking from
the crankcase breather. This can be caused by
combustion gas leakage around the pistons. A dirty
crankcase breather will cause high pressure in the
crankcase. A dirty crankcase breather will cause the
gaskets and the seals to leak.
Engine Oil Leaks into the
Combustion Area of the Cylinders
• Increased engine oil temperature
i01563191
Excessive Bearing Wear Inspect
SMCS Code: 1203-040; 1211-040; 1219-040
When some components of the engine show bearing
wear in a short time, the cause can be a restriction in
a passage for engine oil.
An indicator for the engine oil pressure may show
that there is enough engine oil pressure, but a
component is worn due to a lack of lubrication. In
such a case, look at the passage for the engine oil
supply to the component. A restriction in an engine
oil supply passage will not allow enough lubrication
to reach a component. This will result in early wear.
Engine oil that is leaking into the combustion area of
the cylinders can be the cause of blue smoke. There
are several possible ways for engine oil to leak into
the combustion area of the cylinders:
• Leaks between worn valve guides and valve stems
• Worn components or damaged components
(pistons, piston rings, or dirty return holes for the
engine oil)
• Incorrect installation of the compression ring and/or
the intermediate ring
• Leaks past the seal rings in the turbocharger shaft
• Overfilling of the crankcase
• Wrong dipstick or guide tube
• Sustained operation at light loads
Excessive consumption of engine oil can also
result if engine oil with the wrong viscosity is used.
Engine oil with a thin viscosity can be caused by fuel
leakage into the crankcase or by increased engine
temperature.
77
Testing and Adjusting Section
i01727302
Increased Engine Oil
Temperature - Inspect
SMCS Code: 1348-040
If the engine oil temperature is higher than normal,
the engine oil cooler may have a restriction. Look
for a restriction in the passages for engine oil in
the engine oil cooler. The engine oil pressure will
not necessarily decrease due to a restriction in the
engine oil cooler.
Determine if the engine oil cooler bypass valve is
held in the open position. This condition will allow
the engine oil to flow through the valve rather
than through the engine oil cooler. The engine oil
temperature will increase.
Make sure that the cooling system is operating
properly. A high coolant temperature in the engine oil
cooler will cause high engine oil temperature.
i01554314
Measuring Engine Oil Pressure
SMCS Code: 1304-081
Table 17
Tools Needed
1U-5470 Engine Pressure Group
Qty
1
An incorrect engine oil pressure gauge and an
incorrect engine oil pressure sensor will provide false
indications of low engine oil pressure or high engine
oil pressure. Use the 1U-5470 Engine Pressure
Group to measure the engine oil pressure. Follow
the instructions in Special Instruction, SEHS8907,
“Using the 1U-5470 Engine Pressure Group” that
is included with the tool.
Work carefully around an engine that is running.
Engine parts that are hot, or parts that are moving,
can cause personal injury.
Illustration 82
g00285344
Measure the engine oil pressure to the camshaft and
main bearings on each side of the cylinder block
at oil gallery plug (1). With the engine at operating
temperature, the correct minimum engine oil pressure
at full load rpm is approximately 280 kPa (40 psi).
The correct minimum engine oil pressure at low idle
rpm is approximately 140 kPa (20 psi).
Compare the results to the engine oil pressure that
is indicated on the engine oil pressure gauge and
on the electronic service tool. If there is a notable
difference between the engine oil pressure readings,
determine the cause.
If the engine oil pressure is too low or too high,
determine the cause and correct the condition. If the
engine oil pressure gauge or the engine oil pressure
sensor is incorrect, replace the suspect component.
78
Testing and Adjusting Section
Cooling System
• Coolant loss
• Overcooling
i01411133
General Information (Cooling
System)
SMCS Code: 1350
This engine has a pressure type cooling system. A
pressure type cooling system has two advantages.
• The pressure helps prevent cavitation.
• The risk of boiling is reduced.
Cavitation occurs when mechanical forces cause the
formation of air bubbles in the coolant. The bubbles
can form on the cylinder liners. Collapsing bubbles
can remove the oxide film from the cylinder liner. This
allows corrosion and pitting to occur. If the pressure
of the cooling system is low, the concentration of
bubbles increases. The concentration of bubbles is
reduced in a pressure type cooling system.
The boiling point is affected by three factors:
pressure, altitude, and concentration of glycol in the
coolant. The boiling point of a liquid is increased by
pressure. The boiling point of a liquid is decreased by
a higher altitude. Illustration 83 shows the effects of
pressure and altitude on the boiling point of water.
If the cooling system is not properly maintained,
solids such as scale and deposits reduce the ability
of the cooling system to transfer heat. The engine
operating temperature will increase.
Coolant can be lost by leaks. Overheated coolant can
be lost through the cooling system’s pressure relief
valve. Lower coolant levels contribute to additional
overheating. Overheating can result in conditions
such as cracking of the cylinder head and piston
seizure.
Overcooling is the result of coolant that bypasses the
water temperature regulators and flows directly to
the radiator or heat exchanger. Low load operation
in low ambient temperatures can cause overcooling.
Overcooling is caused by water temperature
regulators that remain open. Overcooling enables
the formation of sludge in the crankcase and carbon
deposits on the valves.
If a problem with the cooling system is suspected,
perform a visual inspection before you perform any
tests on the system.
i01822049
Visual Inspection
SMCS Code: 1350-535
If a problem with the cooling system is suspected,
inspect the cooling system before you perform any
tests on the cooling system.
1. Check the coolant level in the cooling system.
Refer to Operation and Maintenance Manual,
“Cooling System Coolant Level - Check”.
Illustration 83
g00286266
The boiling point of the coolant also depends on the
type of coolant and the concentration of glycol. A
greater concentration of glycol has a higher boiling
temperature. However, glycol transfers heat less
effectively than water. Because of the boiling point
and the efficiency of heat transfer, the concentration
of glycol is important.
Three basic problems can be associated with the
cooling system:
• Overheating
2. Make sure that the coolant meets the
recommendations of the Operation and
Maintenance Manual. Also, make sure that the
coolant has the following properties:
• Color that is similar to new coolant
• Odor that is similar to new coolant
• Free of dirt and debris
3. Look for leaks in the cooling system. After the
engine is stopped, look for coolant or steam from
the radiator’s overflow. Inspect the hoses and
clamps for good condition.
79
Testing and Adjusting Section
If engine oil or coolant is leaking from the joint
between the cylinder head and the engine block,
there is a problem with the cylinder head gasket.
Note: The water pump has a weep hole between
the seal for the coolant and the seal for the bearing.
The weep hole prevents coolant from entering the
lubrication system if there is a problem with a seal in
the water pump. A small amount of coolant at the
weep hole is normal.
4. Make sure that air flows through the radiator and
that there is not a restriction. Look for radiator fins
that are bent, damaged, or leaking. Look for dirt
and debris that can restrict the flow of air through
the fins.
i01279097
Test Tools for the Cooling
System
SMCS Code: 0781; 1350
Table 18
Tools Needed
Quantity
4C-6500
Digital Thermometer
1
8T-2700
Blowby/Air Flow Indicator
1
9U-7400
Multitach
1
9S-8140
Pressurizing Pump
1
5. Inspect the fan drive belts and pulley grooves.
A loose fan drive belt wears at a faster rate
than a belt with the proper tension. A loose belt
can damage the pulleys. A loose belt can slip.
Substances such as oil and grease will cause the
belts to slip.
6. Check for damage to the fan blades. Look for
damaged baffles on the radiator and for baffles
that are missing. Inspect the shroud of the fan for
good condition.
Making contact with a running engine can cause
burns from hot parts and can cause injury from
rotating parts.
When working on an engine that is running, avoid
contact with hot parts and rotating parts.
7. Inspect the air inlet system. Make sure that the
air cleaner, the air inlet, and the exhaust are not
restricted.
8. Look for signs of air or combustion gas in the
coolant.
Air and/or gas in the coolant results in foaming
of the coolant.
Illustration 84
Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap,
stop the engine and wait until the cooling system
components are cool. Loosen the cooling system
pressure cap slowly in order to relieve the pressure.
9. After the engine is cool, remove the cooling system
filler cap slowly in order to release pressure.
Inspect the filler cap. Check the condition of the
gasket. Check the sealing surface for the cap.
The gasket and the sealing surface must be clean
and free of gouges, nicks, and grooves.
g00286267
4C-6500 Digital Thermometer
The 4C-6500 Digital Thermometer is used in the
diagnosis of overheating conditions or overcooling
problems. This group can be used to check
temperatures in several different parts of the cooling
system. Refer to the testing procedure in the
Operating Manual, NEHS0554.
80
Testing and Adjusting Section
The 9S-8140 Pressurizing Pump is used to test
pressure caps. The 9S-8140 Pressurizing Pump is
used to pressure check the cooling system for leaks.
Steam or hot coolant can cause severe burns.
Do not loosen the filler cap or the pressure cap on
a hot engine.
Allow the engine to cool before removing the filler
cap or the pressure cap.
Illustration 85
g00286269
8T-2700 Blowby/Air Flow Indicator
i02051684
The 8T-2700 Blowby/Air Flow Indicator is used
to check the air flow through the radiator core.
Refer to the testing procedure in Special Instruction,
SEHS8712.
Testing the Cooling System
SMCS Code: 1350-081
Testing for Freeze Protection
Table 19
Tools Needed
245-5829 Coolant/Battery Tester (1)
Illustration 86
Qty
1
g00286276
9U-7400 Multitach
The 9U-7400 Multitach is used to check the fan
speed. Refer to the testing procedure in Operator
Manual, NEHS0605.
Illustration 88
g00439083
245-5829 Coolant/Battery Tester
Check the coolant frequently in cold weather for the
proper protection against freezing. Use either the
245-5829 Coolant/Battery Tester in order to ensure
adequate freeze protection. The testers are identical
except for the temperature scale. The testers give
immediate, accurate readings. The testers can be
used for antifreeze/coolants that contain ethylene or
propylene glycol. Instructions are provided with the
testers.
Illustration 87
9S-8140 Pressurizing Pump
g00286369
81
Testing and Adjusting Section
Making the Correct Antifreeze
Mixtures
Adding pure antifreeze as a makeup solution for the
cooling system top-off is an unacceptable practice.
Adding pure antifreeze increases the concentration
of antifreeze in the cooling system. This increases
the concentration of the dissolved solids and the
undissolved chemical inhibitors in the cooling system.
Add the antifreeze and water mixture in the same
concentration as your cooling system. Refer to
Operation and Maintenance Manual, SEBU6711 .
Testing the Supplemental Coolant
Additive and the Glycol
Illustration 90
g00296067
Typical cross section of a filler cap
Refer to the engine’s Operation and Maintenance
Manual for further information about testing the
cooling system.
(1) Sealing surface of both filler cap and radiator
Testing the Filler Cap
Personal injury can result from hot coolant, steam
and alkali.
Table 20
Tools Needed
9S-8140 Pressurizing Pump
Qty
1
At operating temperature, engine coolant is hot
and under pressure. The radiator and all lines
to heaters or the engine contain hot coolant or
steam. Any contact can cause severe burns.
Remove filler cap slowly to relieve pressure only
when engine is stopped and radiator cap is cool
enough to touch with your bare hand.
Cooling System Conditioner contains alkali. Avoid
contact with skin and eyes.
To check for the amount of pressure that opens the
filler cap, use the following procedure:
Illustration 89
g00286369
9S-8140 Pressurizing Pump
The 9S-8140 Pressurizing Pump is used to test the
cooling system for leaks. The pump can also be used
to test the filler cap, the pressure relief valve, and
the pressure gauge.
One cause for a pressure loss from the cooling
system can be a damaged seal on the radiator filler
cap.
1. After the engine cools, carefully loosen the filler
cap in order to release the pressure from the
cooling system. Remove the filler cap.
2. Carefully inspect the filler cap. Look for any
damage to the seals and to the sealing surface.
Remove any deposits that are found.
If the filler cap is damaged, obtain a new cap.
3. Install the filler cap on the 9S-8140 Pressurizing
Pump.
The opening pressure for the filler cap’s pressure
relief valve is stamped on the filler cap.
4. Apply pressure to the filler cap. Compare the
gauge reading with the opening pressure that is
listed on the filler cap.
If the cap cannot sustain the correct pressure,
obtain a new cap.
82
Testing and Adjusting Section
If the filler cap’s pressure relief valve does not
open within approximately 7 kPa (1 psi) of the
pressure that is stamped on the filler cap, obtain
a new cap.
Testing for Air and/or Exhaust Gas
in the Coolant
Air and/or exhaust gas in the coolant causes foaming
and aeration. Bubbles in the cooling system reduce
the heat transfer and the pump flow. Pockets of air or
gas can prevent coolant from contacting parts of the
engine. The pockets allow hot spots to develop.
If the cooling system is not filled to the proper level or
if the system is filled too quickly, air can be trapped
in the system. Leaks from components such as
aftercoolers and hoses can allow air to enter the
system. The inlet of the water pump is a potential
location for the entry of air.
To help prevent air from entering the cooling system,
fill the system slowly. Make sure that all of the hoses
and pipe connections are secure.
If the cylinder head is loose or cracked, exhaust gas
can enter the cooling system. Exhaust gas can also
enter the cooling system through internal cracks
and/or defects in the cylinder head gasket.
Air and/or exhaust gas in the cooling system can
cause overheating. Use the following test to check for
the presence of air and/or exhaust gas in the coolant.
1. Make sure that the cooling system is filled to the
proper level.
2. Remove the plug from the radiator. Install a hose
into the hole for the plug.
3. Fill a glass container with water and place the
other end of the hose into the container.
4. Start the engine. Operate the engine until normal
operating temperature is reached.
5. Observe the end of the hose in the glass container.
A bubble may rise occasionally from the hose.
This is normal.
If a stream of bubbles rise from the hose, air
and/or exhaust gas in the coolant is indicated.
Testing The Radiator And Cooling
System For Leaks
Table 21
Tools Needed
9S-8140 Pressurizing Pump
Qty
1
Use the following procedure in order to check the
cooling system for leaks:
Personal injury can result from hot coolant, steam
and alkali.
At operating temperature, engine coolant is hot
and under pressure. The radiator and all lines
to heaters or the engine contain hot coolant or
steam. Any contact can cause severe burns.
Remove filler cap slowly to relieve pressure only
when engine is stopped and radiator cap is cool
enough to touch with your bare hand.
Cooling System Conditioner contains alkali. Avoid
contact with skin and eyes.
1. After the engine cools, carefully loosen the filler
cap in order to release the pressure from the
cooling system. Remove the filler cap.
2. Ensure that the radiator is filled to the correct level.
3. Install the 9S-8140 Pressurizing Pump onto the
radiator’s filler tube.
Illustration 91
g00769076
4. Increase the pressure reading on the gauge to
20 kPa (3 psi) more than the pressure on the filler
cap.
83
Testing and Adjusting Section
5. Inspect the radiator, all connection points, and the
hoses for leaks.
If no leaks are found and the gauge reading remains
steady for a minimum of five minutes, the cooling
system is not leaking.
If leaking is observed and/or the gauge reading
decreases, make repairs, as needed.
Testing the Water Temperature
Gauge
Table 22
Tools Needed
Quantity
4C-6500 Digital Thermometer (1)
1
2F-7112 Thermometer (1)
1
(1)
Either thermometer may be used.
The 4C-6500 Digital Thermometer is used in the
diagnosis of overheating conditions and overcooling
conditions. This group can be used to check
temperatures in several different parts of the cooling
system. The Operating Manual, NEHS0554 is
provided with the thermometer.
Check the accuracy of the water temperature
indicator or water temperature sensor if you find
either of the following conditions:
• The engine runs at a temperature that is too hot,
but a normal temperature is indicated. A loss of
coolant is found.
• The engine runs at a normal temperature, but a
hot temperature is indicated. No loss of coolant
is found.
Personal injury can result from escaping fluid under pressure.
If a pressure indication is shown on the indicator,
push the release valve in order to relieve pressure
before removing any hose from the radiator.
Making contact with a running engine can cause
burns from hot parts and can cause injury from
rotating parts.
When working on an engine that is running, avoid
contact with hot parts and rotating parts.
Illustration 92
g00743844
Typical example
(1) Water manifold assembly
(2) Plugs
1. Remove one plug (2) from water manifold
assembly (1). Install a probe for the thermometer
into the opening.
Note: A temperature indicator of known accuracy can
also be used for this test.
2. Start the engine. Run the engine until the
temperature reaches the desired range according
to the test thermometer.
If necessary, place a cover over part of the radiator
in order to cause a restriction of the airflow.
3. Compare the reading on the water temperature
gauge with the reading on the test thermometer.
If the readings are within the tolerance for the
range of the water temperature gauge, the gauge
is OK.
If the readings are not within the tolerance for the
range of the water temperature gauge, obtain a
new gauge.
Testing the Water Temperature
Regulator
Personal injury can result from escaping fluid under pressure.
If a pressure indication is shown on the indicator,
push the release valve in order to relieve pressure
before removing any hose from the radiator.
1. Remove the water temperature regulator from the
engine.
84
Testing and Adjusting Section
2. Heat water in a pan until the temperature is 92 °C
(197 °F).
3. Hang the water temperature regulator in the pan
of water. The water temperature regulator must be
below the surface of the water and away from the
sides and the bottom of the pan.
4. Keep the water at the correct temperature for ten
minutes.
5. After ten minutes, remove the water temperature
regulator. Immediately measure the opening in the
water temperature regulator.
If the opening agrees with the distance that is
specified in the engine’s Specifications manual,
the water temperature regulator is operating
properly.
If the distance is less than the distance specified
in the engine’s Specifications manual, obtain a
new water temperature regulator.
Refer to Specifications, “Water Temperature
Regulator”.
Testing the Radiator
Table 23
Tools Needed
Quantity
8T-2700 Blowby/Air Flow Indicator
1
9U-7400 Multitach
1
The 8T-2700 Blowby/Airflow Indicator is used to
check the airflow through the radiator core. The
indicator can also be used to check different areas of
the core in order to locate plugged areas.
It is normal for air flow to be five times greater at the
center and the edges.
For instructions, see Special Instruction, SEHS8712,
“Using the 8T-2700 Blowby/Air Flow Indicator”.
If the air flow is not restricted, check the fan speed.
The 9U-7400 Multitach Tool Group is used to
check the fan speed. For instructions, see the
Operating Manual, NEHS0605 that is supplied with
the multitach.
85
Testing and Adjusting Section
Basic Engine
Main Bearings
i01251748
Cylinder Block
SMCS Code: 1201-040
If the main bearing caps are installed without
bearings, the bore in the block for the main bearings
can be checked. Tighten the nuts that hold the caps
to the torque that is shown in the Specifications.
Alignment error in the bores must not be more
than 0.08 mm (0.003 inch). Refer to the Special
Instruction, SMHS7606 for the correct procedure for
using the 1P-4000 Line Boring Tool Group for the
alignment of the main bearing bores. The 1P-3537
Dial Bore Gauge Group can be used to check the size
of the bores. The Special Instruction, GMGO0981 is
with the group.
Main bearings are available with a larger outside
diameter than the original size bearings. These
bearings are available for the cylinder blocks with
the main bearing bore that is made larger than the
bores’ original size. The size that is available has a
0.63 mm (0.025 inch) outside diameter that is larger
than the original size bearings.
i01673233
Cylinder Liner Projection
SMCS Code: 1216-082
Table 24
Tools Needed
Quantity
1U-9895 Crossblock
1
3H-0465 Push-Puller Plate
2
8F-6123 Bolt
2
3B-1925 Copper Washer
4
0S-1575 Bolt
4
8T-0455 Liner Projection Tool Group
1
1. Make sure that the top surface of the cylinder
block, the cylinder liner bores, the cylinder liner
flanges, and the spacer plates are clean and dry.
Illustration 93
g00285686
1P-3537 Dial Bore Gauge Group
Piston Rings
The 4C-4519 Piston Ring Groove Gauge is available
for checking the top piston ring groove with straight
sides. Refer to Guideline For Reusable Parts,
SEBF8049, “Pistons”.
Connecting Rod Bearings
The connecting rod bearings fit tightly in the bore in
the rod. If the bearing joints are fretted, check the
bore size. This can be an indication of wear because
of a loose fit.
Connecting rod bearings are available with 0.63 mm
(0.025 inch) and 1.27 mm (0.050 inch) smaller
inside diameter than the original size bearing. These
bearings are for crankshafts that have been ground.
Illustration 94
Measuring the cylinder liner projection
(1)
(2)
(3)
(4)
(5)
(6)
3H-0465 Push-Puller Plate
1P-2403 Dial Indicator
1P-2402 Gauge Body
0S-1575 Bolt and 3B-1925 Copper Washer
Spacer plate
1U-9895 Crossblock
g00285687
86
Testing and Adjusting Section
2. Install a new gasket and spacer plate (5) on the
cylinder block.
3. Install the cylinder liner in the cylinder block
without seals or bands.
4. Hold spacer plate (5) and the cylinder liner in
position according to the following procedure:
a. Install four 3B-1925 Copper Washers and four
0S-1575 Bolts(4) around the spacer plate (5).
Tighten the bolts evenly to a torque of 95 N·m
(70 lb ft).
b. Install the following components: 1U-9895
Crossblock (6), two 3H-0465 Push-Puller
Plates (1), and two 8F-6123 Bolts. Ensure
that 1U-9895 Crossblock (6) is in position at
the center of the cylinder liner. Ensure that the
surface of the cylinder liner is clean. Tighten
the bolts evenly to a torque of 70 N·m (50 lb ft).
i01479093
Flywheel - Inspect
SMCS Code: 1156-040
Table 25
Tools Needed
Part
Number
8T-5096
Part Name
Dial Indicator Group
Quantity
1
Face Runout (Axial Eccentricity) Of
The Flywheel
c. Check the distance from the bottom edge of
1U-9895 Crossblock (6) to the top edge of
spacer plate (5). The vertical distance from
both ends of the 1U-9895 Crossblock must
be equal.
5. Use 8T-0455 Liner Projection Tool Group (6) to
measure the cylinder liner projection.
6. Mount 1P-2403 Dial Indicator (2) in 1P-2402
Gauge Body (3). Use the back of the 1P-5507
Gauge Block to zero dial indicator (2).
7. The cylinder liner projection must be
0.059 to 0.199 mm (0.0023 to 0.0078 inch). Read
the measurement on the outer flange of the
cylinder liner at four equally distant positions. Do
not read the measurement on the inner flange.
The maximum allowable difference between the
high measurements and the low measurements
at four positions around each cylinder liner is
0.05 mm (0.002 inch). The maximum allowable
difference between the four measurements must
not exceed 0.05 mm (0.002 inch) on the same
cylinder liner.
Note: If the cylinder liner projection is not within
specifications, turn the cylinder liner to a different
position within the bore. Measure the projection
again. If the cylinder liner projection is not within
specifications, move the cylinder liner to a different
bore. Inspect the top face of the cylinder block.
Note: When the cylinder liner projection is correct,
put a temporary mark on the cylinder liner and the
spacer plate. Be sure to identify the particular cylinder
liner with the corresponding cylinder. When the seals
and the filler band are installed, install the cylinder
liner in the marked position.
Illustration 95
g00286049
Checking face runout of the flywheel
1. Refer to illustration 95 and install the dial indicator.
Always put a force on the crankshaft in the same
direction before the dial indicator is read. This will
remove any crankshaft end clearance.
2. Set the dial indicator to read 0.0 mm (0.00 inch).
3. Turn the flywheel at intervals of 90 degrees and
read the dial indicator.
4. Take the measurements at all four points. Find
the difference between the lower measurements
and the higher measurements. This value is the
runout. The maximum permissible face runout
(axial eccentricity) of the flywheel must not exceed
0.15 mm (0.006 inch).
87
Testing and Adjusting Section
Bore Runout (Radial Eccentricity)
Of The Flywheel
g00286058
Illustration 97
Flywheel clutch pilot bearing bore
5. Take the measurements at all four points. Find the
difference between the lower measurements and
the higher measurements. This value is the runout.
The maximum permissible pilot bore runout of the
flywheel must not exceed 0.13 mm (0.005 inch).
g00286054
Illustration 96
Checking bore runout of the flywheel
(1)
(2)
(3)
(4)
7H-1945
7H-1645
7H-1942
7H-1940
Holding Rod
Holding Rod
Dial Indicator
Universal Attachment
1. Install the 7H-1942 Dial Indicator (3). Make an
adjustment of the 7H-1940 Universal Attachment
(4) so that the dial indicator makes contact on
the flywheel.
2. Set the dial indicator to read 0.0 mm (0.00 inch).
3. Turn the flywheel at intervals of 90 degrees and
read the dial indicator.
i01563287
Flywheel Housing - Inspect
SMCS Code: 1157-040
Table 26
Tools Needed
8T-5096
Dial Indicator Group
Quantity
1
Face Runout (Axial Eccentricity) Of
The Flywheel Housing
4. Take the measurements at all four points. Find
the difference between the lower measurements
and the higher measurements. This value is the
runout. The maximum permissible bore runout
(radial eccentricity) of the flywheel must not
exceed 0.15 mm (0.006 inch).
Illustration 98
g00285931
Checking face runout of the flywheel housing
If you use any other method except the method that
is given here, always remember that the bearing
clearance must be removed in order to receive the
correct measurements.
88
Testing and Adjusting Section
1. Fasten a dial indicator to the flywheel so the anvil
of the dial indicator will contact the face of the
flywheel housing.
2. Put a force on the crankshaft toward the rear
before the dial indicator is read at each point.
Illustration 101
Illustration 99
g00285932
Checking face runout of the flywheel housing
g00285936
2. While the dial indicator is in the position at location
(C) adjust the dial indicator to 0.0 mm (0.00 inch).
Push the crankshaft upward against the top of
the bearing. Refer to the illustration 101. Write
the measurement for bearing clearance on line 1
in column (C).
3. Turn the flywheel while the dial indicator is set at
0.0 mm (0.00 inch) at location (A). Read the dial
indicator at locations (B), (C) and (D).
Note: Write the measurements for the dial indicator
with the correct notations. This notation is necessary
for making the calculations in the chart correctly.
4. The difference between the lower measurements
and the higher measurements that are performed
at all four points must not be more than 0.38 mm
(0.015 inch), which is the maximum permissible
face runout (axial eccentricity) of the flywheel
housing.
3. Divide the measurement from Step 2 by two. Write
this number on line 1 in columns (B) and (D).
4. Turn the flywheel in order to put the dial indicator
at position (A). Adjust the dial indicator to 0.0 mm
(0.00 inch).
Bore Runout (Radial Eccentricity)
Of The Flywheel Housing
Illustration 102
g00285932
Checking bore runout of the flywheel housing
Illustration 100
g00285934
Checking bore runout of the flywheel housing
1. Fasten a dial indicator to the flywheel so the anvil
of the dial indicator will contact the bore of the
flywheel housing.
5. Turn the flywheel counterclockwise in order to
put the dial indicator at position (B). Write the
measurements in the chart.
6. Turn the flywheel counterclockwise in order to
put the dial indicator at position (C). Write the
measurement in the chart.
89
Testing and Adjusting Section
7. Turn the flywheel counterclockwise in order to
put the dial indicator at position (D). Write the
measurement in the chart.
8. Add the lines together in each column.
9. Subtract the smaller number from the larger
number in column B and column D. Place this
number on line III. The result is the horizontal
eccentricity (out of round). Line III in column C is
the vertical eccentricity.
The damper is mounted to the crankshaft on the front
of the engine. Damage to the failure or failure of
the damper will increase vibrations. The increase in
vibrations will result in damage to the crankshaft and
to other engine components. A deteriorating damper
will cause more gear train noise at variable points
in the speed range.
A damper that is hot may be the result of excessive
friction. This could be due to excessive torsional
vibration or misalignment. Use an infrared
thermometer to monitor the temperature of the
damper during operation. If the temperature reaches
100 °C (212 °F), consult your Caterpillar dealer.
Inspect the damper for evidence of dents, cracks,
and leaks of the fluid.
If a fluid leak is found, determine the type of fluid. The
fluid in the damper is silicone. Silicone is transparent,
smooth, and viscous. It is difficult to remove silicone
from most surfaces.
If the fluid leak is engine oil, inspect the crankshaft
seals for leaks. If a leak is observed, replace the
crankshaft seals.
Inspect the damper. Repair the damper or replace
the damper for any of the following reasons:
• The damper is dented, cracked, or leaking.
Illustration 103
g00286046
Graph for total eccentricity
(1)
(2)
(3)
(4)
• The paint on the damper is discolored from heat.
• The engine has had a failure because of a broken
crankshaft.
Total vertical eccentricity
Total horizontal eccentricity
Acceptable value
Unacceptable value
• Analysis of the engine oil has revealed that the
front main bearing is badly worn.
10. On the graph for total eccentricity, find the point
of intersection of the lines for vertical eccentricity
and horizontal eccentricity.
• There is a large amount of gear train wear that is
11. The bore is in alignment, if the point of intersection
is in the range that is marked “Acceptable”. If the
point of intersection is in the range that is marked
“Not acceptable”, the flywheel housing must be
changed.
For instructions on repairing the damper, refer to
Guide for Reusable Parts, SEBF8152, “Procedures to
Rebuild Vibration Dampers 3600 Family of Engines”.
The tools and instructions in the guide for reusable
parts are appropriate for G3500 Engines.
i01564729
Vibration Damper - Check
SMCS Code: 1205-535
The crankshaft vibration damper limits the torsional
vibration of the crankshaft. The visconic damper has
a weight that is located inside a fluid filled case.
not caused by a lack of engine oil.
90
Testing and Adjusting Section
Air/Electric Starting System
i01433812
General Information
(Air/Electric Starting System)
2. Check the electrical system by disconnecting the
leads from the control valve (1) at connector (2).
Set the multimeter in the “DCV” range. Measure
voltage across the disconnected leads that
connect to the starting switch.
a. A voltage reading shows that the problem is in
the control valve (2) or the air starting motor.
Go to Step 2 of Air Side Of The Air System.
SMCS Code: 1450
This starting system uses an electric solenoid to
position an air valve in order to activate the air
starting motor. If the starting motor does not function,
do the procedure that follows:
1. Check the indicator reading for the air pressure.
b. A “ZERO” reading shows that the problem is in
the control switch or the problem is in the wires
for the control switch.
3. Fasten the multimeter lead to the start switch at
the terminal for the wire from the battery. Fasten
the other lead to a good ground.
2. If the reading is not acceptable then use a remote
source to charge the system.
a. A “ZERO” reading indicates a broken circuit
from the battery. With this condition, check the
circuit breaker and wiring.
3. If the reading is acceptable then open the main
tank drain valve for a moment. Verify the pressure
that is shown on the pressure indicator. Listen for
the sound of the high pressure from the discharge.
b. The problem is in the control switch if either a
voltage reading is found at the control switch or
if a voltage reading is found in the wires from
the control switch to the control valve.
Electrical Side Of The Air System
1. Move the start control switch in order to activate
the starting solenoids. Listen for the sound of the
engagement of the air starter motor pinion with
the flywheel gear.
Air Side Of The Air System
a. If the sound of the engagement can be heard,
the problem is with the Air Side Of The Air
System. Proceed to the Air Side Of The Air
System.
b. If no sound of the engagement can be heard,
the problem could be with the Electrical Side
Of The Air System.
Illustration 105
g00286937
Air starting system (typical example)
(1)
(2)
(3)
(4)
(5)
Control valve
Connector
Connection
Air hose
Relay valve
1. Activate the control switch. If the engagement of
the air starter motor pinion with the flywheel ring
gear can be heard then remove the small air hose
(4) from the top of the relay valve (5).
Illustration 104
Control valve (typical example)
(1) Control valve
(2) Connector
g00286936
a. Full air pressure comes from the end of the air
hose (4) when the control switch is activated.
The relay valve (5) is worn or the air starting
motor is damaged.
91
Testing and Adjusting Section
b. If no air pressure comes from the end of the air
hose (4), then the problem is in the pinion nose
housing for the air starting motor.
2. The sound of the air starter motor pinion is not
heard when the control switch is activated. Voltage
was measured at the control valve. Remove the
other small air hose from the connection (3).
a. If no air comes from the end of the removed air
hose, the control valve (1) is worn.
b. If the air comes from the end of the removed
hose, then the problem is in the pinion nose
housing for the air starting motor.
92
Testing and Adjusting Section
Electrical System
i01936315
Test Tools for the Electrical
System
SMCS Code: 0785
Table 27
Tools Needed
Quantity
4C-4911
Battery Load Tester
1
225-8266
Ammeter Tool Gp
1
146-4080
Digital Multimeter
1
Most of the tests of the electrical system can be done
on the engine. The wiring insulation must be in good
condition. The wire and cable connections must be
clean and tight. The battery must be fully charged. If
the on-engine test shows a defect in a component,
remove the component for more testing.
The service manual Testing And Adjusting Electrical
Components, REG00636 has complete specifications
and procedures for the components of the starting
circuit and the charging circuit.
The 4C-4911 Battery Load Tester is a portable unit
in a metal case. The 4C-4911 Battery Load Tester
can be used under field conditions and under high
temperatures. The tester can be used to load test
all 6, 8, and 12 Volt batteries. This tester has two
heavy-duty load cables that can easily be fastened
to the battery terminals. A load adjustment knob is
located on the top of the tester. The load adjustment
knob permits the current that is being drawn from
the battery to be adjusted to a maximum of 1000
amperes. The tester is cooled by an internal fan that
is automatically activated when a load is applied.
The tester has a built-in LCD. The LCD is a digital
voltmeter. The LCD is a digital meter that will
also display the amperage. The digital voltmeter
accurately measures the battery voltage at the
battery. This measurement is taken through tracer
wires that are buried inside the load cables. The
digital meter, that displays the amperage, accurately
displays the current that is being drawn from the
battery which is being tested.
Note: Refer to Operating Manual, SEHS9249
for more complete information for the use of the
4C-4911 Battery Load Tester.
Illustration 107
g01012117
225-8266 Ammeter Tool Gp
Illustration 106
4C-4911 Battery Load Tester
g00283565
The 225-8266 Ammeter Tool Gp is a completely
portable, self-contained instrument that allows
electrical current measurements to be made without
breaking the circuit or without disturbing the insulation
on the conductors. A digital display is located on the
ammeter for reading current directly in a range from
1 to 1200 amperes. If a 6V-6014 Cable is connected
between this ammeter and a digital multimeter, a
current reading of less than 1 ampere can be read
directly from the screen of the multimeter.
93
Testing and Adjusting Section
A lever is used to open the jaw over the conductor
up to a diameter of 23 mm (0.90 inch). The spring
loaded jaw is then closed around the conductor for
the measurement of current. The selector switch is
rotated to the appropriate range. A “HOLD” button
allows the last reading to be sustained on the display.
This allows measurements to be taken in limited
access areas. Power for the ammeter is supplied by
batteries which are located inside the tool.
Note: Refer to the User’s Guide for more complete
information for the use of the ammeter. The guide is
packaged with the unit.
i01305428
Battery
SMCS Code: 1401-081
Never disconnect any charging unit circuit or battery circuit cable from the battery when the charging unit is operated. A spark can cause an explosion from the flammable vapor mixture of hydrogen and oxygen that is released from the electrolyte through the battery outlets. Injury to personnel can be the result.
The battery circuit is an electrical load on the charging
unit. The load is variable because of the condition of
the charge in the battery.
NOTICE
The charging unit will be damaged if the connections
between the battery and the charging unit are broken
while in operation. Damage occurs because the load
from the battery is lost and because there is an increase in charging voltage. High voltage will damage
the charging unit, the regulator, and other electrical
components.
Illustration 108
g01015638
146-4080 Digital Multimeter
The 146-4080 Digital Multimeter is a portable
instrument with a digital display. This multimeter is
built with extra protection against damage in field
applications. The multimeter can display Pulse Width
Modulation (PWM). The multimeter has an instant
ohms indicator that permits the checking of continuity
for fast circuit inspection. The multimeter can also be
used for troubleshooting capacitors that have small
values.
Note: Refer to Operator’s Manual, NEHS0678 for
complete information for the use of the multimeter.
The operator’s manual is packaged with the unit.
Use the 4C-4911 Battery Load Tester in order to
test a battery that does not maintain a charge when
the battery is active. Refer to Operating Manual,
SEHS9249 for detailed instruction on the use of
the 4C-4911 Battery Load Tester. See Special
Instruction, SEHS7633 for the correct procedure
and for the specifications to use when you test the
batteries.
94
Index Section
Index
A
Aftercooler ............................................................. 33
Air Inlet and Exhaust System .......................... 33, 70
Air Starting System................................................ 47
Air/Electric Starting System ................................... 90
Air/Fuel Ratio Control ............................................ 30
Charge Density Feedback ................................. 33
Input from the Customer .................................... 31
Open Loop Mode ............................................... 32
Air/Fuel Ratio Control - Adjust ............................... 64
Alternator ............................................................... 52
B
Basic Engine.................................................... 43, 85
Battery ................................................................... 93
C
Camshaft ............................................................... 46
Camshaft Timing ................................................... 66
Timing Adjustment ............................................. 67
Timing Check ..................................................... 66
Circuit Breaker....................................................... 54
Compression ......................................................... 72
Compressor Bypass .............................................. 34
Cooling System ............................................... 40, 78
Jacket Water System ......................................... 41
Separate Circuit ................................................. 43
Crankshaft ............................................................. 45
Crankshaft Position for Valve Lash Setting ........... 75
Cylinder Block........................................................ 85
Connecting Rod Bearings .................................. 85
Main Bearings .................................................... 85
Piston Rings....................................................... 85
Cylinder Block, Liners and Heads ......................... 43
Cylinder Liner Projection ....................................... 85
D
Detonation Sensor................................................. 60
E
Electric Starting System ........................................ 49
Electrical System ............................................. 49, 92
Electronic Control Module (ECM) ............................ 9
G3516 .................................................................. 9
G3520 .................................................................. 9
Electronic Control System ................................. 5, 56
Electronic Control System Operation ...................... 5
G3516 .................................................................. 5
G3520 .................................................................. 7
Electronic Control System Parameters.................. 13
Air/Fuel Ratio Control......................................... 14
Configuration Parameters .................................. 13
Information for the ECM..................................... 19
Monitoring and Protection .................................. 17
Power Monitoring ............................................... 18
Speed Control .................................................... 15
Start/Stop Control Parameters........................... 16
Timing Control.................................................... 14
Electronic Service Tools ........................................ 22
Caterpillar Electronic Technician (ET)................ 23
Engine Design ......................................................... 4
Engine Governing................................................... 11
Engine Governing - Adjust..................................... 58
Governor Type ................................................... 59
Engine Monitoring System..................................... 23
Monitoring Parameters....................................... 24
Engine Sensors ..................................................... 19
Engine Speed/Timing Sensor ................................ 60
Timing Calibration .............................................. 61
Excessive Bearing Wear - Inspect......................... 76
Excessive Engine Oil Consumption - Inspect........ 76
Engine Oil Leaks into the Combustion Area of the
Cylinders .......................................................... 76
Engine Oil Leaks on the Outside of the Engine.. 76
Exhaust Manifold ................................................... 35
F
Finding the Top Center Position for the No. 1
Piston................................................................... 65
Flywheel - Inspect.................................................. 86
Bore Runout (Radial Eccentricity) Of The
Flywheel ........................................................... 87
Face Runout (Axial Eccentricity) Of The
Flywheel ........................................................... 86
Flywheel Housing - Inspect ................................... 87
Bore Runout (Radial Eccentricity) Of The Flywheel
Housing ............................................................ 88
Face Runout (Axial Eccentricity) Of The Flywheel
Housing ............................................................ 87
Fuel System..................................................... 27, 64
Fuel System Operation.......................................... 27
G
General Information (Air/Electric Starting
System)................................................................
Air Side Of The Air System ................................
Electrical Side Of The Air System......................
General Information (Cooling System) ..................
90
90
90
78
95
Index Section
General Information (Electronic Control System) .. 56
Changing the Settings of the Monitoring
System ............................................................. 58
Connecting the Caterpillar Electronic Technician
(Cat ET) to the Electronic Control Module
(ECM)............................................................... 56
Recommendations for Programming the System
Configuration Parameters ................................ 57
General Information (Fuel System) ....................... 64
General Information (Lubrication System)............. 76
Grounding Practices .............................................. 51
I
Ignition System ...................................................... 25
G3516 ................................................................ 25
G3520 ................................................................ 26
Ignition Transformers and Spark Plugs.............. 26
Ignition Transformer .............................................. 61
Spark Plug ......................................................... 63
Important Safety Information ................................... 2
Increased Engine Oil Temperature - Inspect ......... 77
Integrated Temperature Sensing Module .............. 12
L
Lubrication System .......................................... 38, 76
M
Manifold Air Pressure Sensor................................
Measuring Engine Oil Pressure.............................
Measuring Exhaust Temperature...........................
Measuring Inlet Manifold Temperature ..................
59
77
71
71
P
Pistons, Rings and Connecting Rods .................... 45
Power Supply ........................................................ 51
Requirements for the Control System................ 51
R
Restriction of Air Inlet and Exhaust .......................
Aftercooler Differential Pressure ........................
Air Inlet Restriction.............................................
Exhaust Restriction ............................................
70
70
70
70
S
Start/Stop Control .................................................. 10
Starting Motor ........................................................ 53
Starting Motor Protection ................................... 54
Starting Solenoid ................................................... 53
Systems Operation Section ..................................... 4
T
Table of Contents..................................................... 3
Test Tools for the Cooling System ......................... 79
Test Tools for the Electrical System....................... 92
Testing and Adjusting Section ............................... 56
Testing the Cooling System ................................... 80
Making the Correct Antifreeze Mixtures............. 81
Testing for Air and/or Exhaust Gas in the
Coolant............................................................. 82
Testing for Freeze Protection ............................. 80
Testing the Filler Cap ......................................... 81
Testing the Radiator ........................................... 84
Testing The Radiator And Cooling System For
Leaks................................................................ 82
Testing the Supplemental Coolant Additive and the
Glycol ............................................................... 81
Testing the Water Temperature Gauge .............. 83
Testing the Water Temperature Regulator ......... 83
Turbocharger ......................................................... 36
V
Valve Lash and Valve Bridge Adjustment ..............
Valve Bridge Adjustment....................................
Valve Lash Adjustment ......................................
Valve Lash Check ..............................................
Valve System Components ...................................
Vibration Damper - Check .....................................
Visual Inspection ...................................................
72
73
74
72
36
89
78
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