HOW TO USE THIS COMPETENCY-BASED LEARNING MATERIAL?
Welcome!
The unit of competency, “DIAGNOSE AND OVERHAUL ENGINE
MECHANICAL SYSTEM is one of the competencies of AUTOMOTIVE
SERVICING (ENGINE REPAIR) NCII, a course that comprises the
knowledge, skills, and attitudes required for a TVET trainer to possess.
The module, DIAGNOSE AND OVERHAUL ENGINE MECHANICAL
SYSTEM, contains training materials and activities related to identifying
learner’s
requirements,
preparing
session
plans,
preparing
basic
instructional materials, and organizing learning and teaching activities for
you to complete.
In this module, you are required to go through a series of learning
activities in order to complete each learning outcome. In each learning
outcome are Information Sheets, Self-Checks, Operation Sheets, and
Task/Job Sheets. Follow and perform the activities on your own. If you have
questions, do not hesitate to ask for assistance from your facilitator.
Remember to:

Work through all the information and complete the activities in each
section.

Read information sheets and complete the self-check. Suggested
references are included to supplement the materials provided in this
module.

Most probably, your trainer will also be your supervisor or manager.
He is there to support you and show you the correct way to do things.

You will be given plenty of opportunities to ask questions and practice
on the job. Make sure you practice your new skills during regular work
shifts. This way, you will improve your speed, memory, and your
confidence.

Use the Self-Checks, Operation Sheets, or Task or Job Sheets at the
end of each section to test your own progress. Use the Performance
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
Document No.:
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Criteria Checklist or Procedural Checklist located after the sheet to
check your own performance.

When you feel confident that you have had sufficient practice, ask your
Trainer to evaluate you. The results of your assessment will be
recorded in your Progress Chart and Accomplishment Chart.
Congratulations! If you can complete all the modules, you are ready
for the national assessment in ALT NCII.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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AUTOMOTIVE SERVICING (ENGINE REPAIR) NCII
COMPETENCY-BASED LEARNING MATERIALS
List of Competencies
BASIC COMPETENCIES
NO.
UNIT OF COMPETENCIES
MODULE TITLE
CODE
1
Participate in workplace
communication
Participate in workplace
communication
400311210
2
Work in team environment
Work in team environment
3
Solve/address general
workplace problems
Solve/address general
workplace problems
400311212
4
Develop career and life
decisions
Develop career and life
decisions
400311213
5
Contribute to workplace
innovation
Contribute to workplace
innovation
400311214
6
Present relevant information
Present relevant
information
400311215
Practice occupational safety
and health policies and
procedures
400311216
7
Practice occupational safety
and health policies and
procedures
Exercise efficient and
effective sustainable
practices in the
workplace
400311217
8
Exercise efficient and effective
sustainable practices in the
workplace
9
Practice entrepreneurial skills
in the workplace
Practice entrepreneurial
skills in the workplace
400311211
400311218
COMMON COMPETENCIES
NO.
UNIT OF COMPETENCIES
MODULE TITLE
CODE
1
Validate vehicle specification
Validate vehicle
specification
ALT723211
Automotive Servicing
(Engine Repair) NC II
Date Developed:
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Diagnose and repair
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system
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2
Move and position vehicle
Move and position vehicle
ALT723212
3
Utilize automotive tools
Utilize automotive tools
ALT723213
4
Perform mensuration and
calculation
Perform mensuration and
calculation
ALT723214
5
Utilize workshop facilities and
equipment
Utilize workshop facilities
and equipment
ALT723215
6
Prepare servicing parts and
consumables
Prepare servicing parts and
consumables
ALT723216
7
Prepare vehicle for servicing
and releasing
Prepare vehicle for servicing
ALT723217
and releasing
CORE COMPETENCIES
NO.
UNIT OF COMPETENCIES
MODULE TITLE
CODE
1
Diagnose and repair engine
cooling and lubrication system
Diagnose and repair engine
cooling and lubrication
system
ALT23399
2
Diagnose and repair intake
and exhaust system
Diagnose and repair intake
and exhaust system
ALT233100
3
Diagnose and overhaul the
engine's mechanical system
Diagnose and overhaul the
engine's mechanical system
ALT233101
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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MODULE CONTENT
UNIT OF COMPETENCY:
DIAGNOSE AND OVERHAUL ENGINE
MECHANICAL SYSTEM
MODULE TITLE
:
DIAGNOSING AND OVERHAULING ENGINE
MECHANICAL SYSTEM
MODULE DESCRIPTOR:
This
unit
describes
the
performance
outcomes required to diagnose and repair
faults in the conventional intake and
exhaust
manifold,
throttle
system,
turbocharger, and intercooler system. It
covers the knowledge, skills, and attitude
required to prepare to diagnose and repair
intake and exhaust system, diagnose and
repair intake and exhaust systems and
complete work processes
NOMINAL DURATION
:
QUALIFICATION LEVEL :
20 hours
AUTOMOTIVE SERVICING NCII
SUMMARY OF LEARNING OUTCOMES
Upon completion of this module, the trainee/student must be able to:
LO1. Prepare to diagnose engine mechanical system
LO2. Diagnose engine mechanical system
LO3. Repair engine mechanical system
LO4. Complete work processes
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
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ASSESSMENT CRITERIA
1.
2.
Job requirements are determined from workplace instructions.
Diagnostic information is sourced and interpreted according to
workplace procedures.
3.
Symptoms are verified using a troubleshooting guide.
4.
Hazards associated with the work are identified and risks are
managed.
5.
Tools, equipment, and materials are selected and checked for
serviceability.
6.
Non-serviceable tools and equipment are reported following
workplace procedures.
7.
Availability of materials are checked and reported following
workplace procedures.
8.
Diagnostic tests are performed according to industry criteria.
9.
Inspection is carried out according to industry criteria
10.
Inspection
results
are
compared
with
manufacturer
specifications
11.
Faults are identified from diagnostic test results and causes of
faults are determined.
12.
Findings and recommendations are reported according to
industry criteria.
13.
Safety practices are applied following Occupational Safety and
Health Standards (OSHS) procedure.
14.
Repair information is sourced and interpreted.
15.
Repair options are analyzed and those most appropriate to the
circumstances are selected.
16.
Repair tools, equipment, and, materials are selected and
checked.
17.
Repair options are carried out according to industry criteria
18.
Post-repair testing is carried out according to workplace
procedures
19.
Safety practices are applied following Occupational Safety and
Health Standards (OSHS) procedure.
20.
Final inspection is made based on workplace procedure
21.
Vehicle is turned over to immediate superior for quality control
following workplace procedure.
22.
Work area is restored following 5S of good housekeeping.
23.
Wastes are managed following environmental rules and
regulations.
24.
Tools and equipment are checked and stored according to
workplace procedures.
25.
Workplace documents are processed according to workplace
procedures.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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LEARNING OUTCOME NO.1
PREPARE TO DIAGNOSE AND ENGINE MECHANICAL SYSTEM
Contents:
1. Crafting Job Requirements through Workplace Instructions
2. Operational Fitness of Tools, Equipment, and Materials
Assessment Criteria
LO1: Prepare to diagnose engine mechanical system.
 Job requirements are determined from workplace instructions.
 Diagnostic information is sourced and interpreted according to
workplace procedures.
 Symptoms are verified using a troubleshooting guide.
 Hazards associated with the work are identified and risks are
managed.
 Tools, equipment, and materials are selected and checked for
serviceability.
 Non-serviceable tools and equipment are reported following
workplace procedures.
 Availability of materials are checked and reported following
workplace procedures.
Conditions
The participants will have access to:
The students must be provided with the following:
1. WORKPLACE LOCATION
2. TOOLS
 Basic hand tools
 Feeler gauge
 Straight gauge
 Piston ring compressor
 Torque wrench
 Angle gauge
 Dial and bore gauge
 Vernier caliper
 Micrometer and stand
 Pullers and installers
 Compression tester
 Ridge reamer
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran






Special tools based
on manufacturer’s
standards
Valve
spring
compressor
Oiler
Steel square
Mechanic
stethoscope
V-block
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3. EQUIPMENT
 Engine hydraulic crane
 Chain block
 Engine stand
 Vehicle Lifter
 Crocodile jack
 Jack stand
 Press machine
 Honing
 Valve grinder
 Valve refacer
 Water heater




4. MATERIALS
 Rags
 Degreaser
 Engine oil
 Penetrating oil
 Plastigauge
 Valve lap
 Grinding compound





Surface plate
Pressure gauge
Bench vise
Bench grinder with
steel brush
Wash basin
Parts tray
Overhauling table
Trolley
Oil bucket







Overhauling gasket
Adhesive and sealant
Sanding paper
Sealant
Grinding stick
Crocus cloth
Kerosene
5. TRAINING MATERIALS
 Learning Packages
 Ball pens
 Whiteboard marker
Assessment Method:
1. Self-paced learning
2. Hands-on
3. Demonstration/
Simulation
4. Written Examination
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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Learning Experiences
Learning Outcome No. 1
Assemble Computer Hardware
Learning Activities
Reading information sheet
3.1.1
Answering Self-check
3.1-1
Demonstration
3.1-1
Reading information sheet
3.1.2
Answering Self-check
3.1-2
Demonstration
3.1-2
Reading information sheet
3.1.3
Answering Self-check
3.1-3
Demonstration
3.1-3
Reading information sheet
3.1.4
Special Instructions
If you have some difficulties to
understand the content of the
information sheets don’t hesitate to
approach your facilitator
Compare your answer to the answer
key 3.1-1. If you got a passing score
you now move to the information
sheet 3.1-2. If not review the
information sheet and go over the
self-check again.
Evaluate using the Performance
Criteria check 3.1-1
If you have some difficulties to
understand the content of the
information sheets don’t hesitate to
approach your facilitator
Compare your answer to the answer
key 3.1-2. If you got a passing score
you now move to the information
sheet 3.1-2. If not review the
information sheet and go over the
self-check again.
Evaluate using the Performance
Criteria check 3.1-2
If you have some difficulties to
understand the content of the
information sheets don’t hesitate to
approach your facilitator
Compare your answer to the answer
key 3.1-3. If you got a passing score
you now move to the information
sheet 3.1-3. If not review the
information sheet and go over the
self-check again.
Evaluate using the Performance
Criteria check 3.1-3
If you have some difficulties to
understand the content of the
information sheets don’t hesitate to
approach your facilitator
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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Answering Self-check
3.1-4
Demonstration
3.1-4
Compare your answer to the answer
key 3.1-4. If you got a passing score
you now move to the information
sheet 3.1-4. If not review the
information sheet and go over the
self-check again.
Evaluate using the Performance
Criteria check 3.1-4
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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Information Sheet 3.1-1
PREPARING TO DIAGNOSE ENGINE MECHANICAL SYSTEM.
Learning Objectives:
After reading this INFORMATION SHEET, YOU MUST be able to
1. Familiarize oneself with a variety of diagnostic tools used in the
assessment of engine mechanical systems.
2. Develop practical skills in employing diagnostic techniques, including
visual inspection, data analysis, and performance testing.
3. Gain expertise in interpreting diagnostic results to pinpoint potential
issues within the engine mechanical system and formulating effective
troubleshooting strategies.
Introduction
In the dynamic landscape of automotive technology, the effective diagnosis of
engine mechanical systems stands as a crucial skill for automotive
professionals and enthusiasts alike. The task of preparing to diagnose engine
mechanical systems involves a multifaceted approach that extends beyond
mere theoretical knowledge. This comprehensive study aims to equip
individuals with the essential tools and skills needed to navigate the intricate
intricacies of internal combustion engines.
As we delve into this exploration, our focus lies on familiarizing ourselves with
a diverse array of diagnostic tools specifically designed for assessing engine
mechanical systems. This encompasses a spectrum of instruments, from
traditional compression testers to advanced oscilloscopes. The objective is not
only to understand the intricacies of these tools but also to develop proficiency
in their application.
Practical skills take center stage in this journey, emphasizing hands-on
experiences that involve the disassembly, inspection, and reassembly of
engine components. Through these activities, participants will cultivate a
tactile understanding of engine intricacies, setting the foundation for effective
diagnosis. This hands-on approach extends to the employment of diagnostic
techniques, including visual inspection, data analysis, and performance
testing.
Furthermore, our exploration encompasses the crucial aspect of result
interpretation. Acquiring expertise in deciphering diagnostic outputs is pivotal
for identifying potential issues within the engine mechanical system
accurately. With this proficiency, individuals will be empowered to formulate
effective troubleshooting strategies, enabling them to address problems at
their root cause and restore optimal engine performance.
Embark on this educational journey, where theory meets practice, and
theoretical knowledge transforms into actionable skills. The study of
preparing to diagnose engine mechanical systems is an essential step towards
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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mastery in the realm of automotive diagnostics, providing the tools and
insights necessary to unravel the mysteries beneath the hood.
Safety precautions in the working area
Individual protections
The wearing of individual protection equipment (EPI) is compulsory to work
safely on any operation.
The following items of personal protective equipment are compulsory:
o Trousers/overalls or a suitable combination
o Safety shoes
Depending on the location and the type of operation, these items of individual
protection equipment are compulsory:
o Safety helmet, when operating underneath the vehicle
o Protection goggles, when working on fluid circuits, fuel circuits, air
circuits, etc., or for operations that could involve the suspension or
projection of particles in the air
o Face masks, for operations that could involve the suspension or
projection of particles in the air
o Safety gloves, to guard against cuts or exposure to chemical products
o Ear protection, when working in a noisy environment
All these items of individual protection equipment are available in your Parts
shop.
Place a protective cover on the following:
o Front wings
o Driver's seat
o Floor carpet (driver's side)
o The steering wheels
Working area
The working area should be clean and
tidy.
Environment
Respect the environmental regulations:
o Separation and collection of waste
o Ejection of used water
o Air pollution
o Noise emissions
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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Tools, Equipment, and Materials are necessary for Diagnosing and
Overhaul Engine Mechanical. What they are, what they can be used for, and
how to use them are of great importance to the Technician.
TOOLS
1. Feeler gauge
A feeler gauge is a type of linear
measurement tool. They are widely
used by a variety of professionals,
particularly in engineering and
mechanical applications. They are
especially common in automotive
repair and maintenance tool bags.
Typical measurements you might
want to check using a feeler gauge
include
tappet
clearances,
distributor points, spark plug gaps,
bearing clearances, and piston ring
gaps. You can also buy models
suitable for a variety of other uses,
such as a guitar feeler gauge.
2. Straight edge
A straightedge or straight
edge is a tool used for drawing
straight lines or checking their
straightness. If it has equally spaced
markings along its length, it is
usually called a ruler.
Straightedges are used in the
automotive service and machining
industry to check the flatness of
machined mating surfaces. They are
also used in the decorating industry
for cutting and hanging wallpaper.
3. Piston ring compressor
A piston ring compressor is a
compressor that features pistons fit
inside
of
a
cylinder
using
compression rings that seal between
the piston and cylinder wall. The
piston moves up and down by use of
a connecting rod attached from the
piston to a crankshaft. Piston Ring
compressors
are
usually
oillubricated to enable the rings to slide
easily against the cylinder walls.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
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system
Developed by:
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Piston rings are usually made from a
machined aluminum ring or spring
steel. At BOGE, we provide the
design and manufacturing of various
types of compressor technologies,
including piston ring compressors.
4. Torque Wrench
Utilized
for
checking
and
adjusting the tightening torque of
components such as bolts, screws,
or nuts, torque wrenches play a vital
role across diverse industries such
as
automotive,
construction,
manufacturing, as well as aerospace.
These
technologically
advanced
devices are essential for precision,
guaranteeing a secure fastening of
components while minimizing the
potential for overload or structural
damage.
Using a torque involves setting
the desired torque level and applying
force until the wrench signals that
the preset torque has been reached.
This ensures that the fastener is
tightened to the recommended
specifications.
To effectively use and configure your
torque wrench, follow these step-bystep guidelines:
• Determine the Torque Value:
Begin by identifying the required
torque value. Consult your user
manual or check online resources for
this information. Ensure that you
are referencing the correct scale on
your torque wrench, which typically
provides lb·ft on one side and lb·ft or
N.m on the other.
• Loosen the Knob:
Start by releasing the knob located at
the bottom of the torque wrench.
This action allows the handle to
move freely back and forth.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
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Set the Torque: If, for instance, the
specified torque is 100 lb·ft, rotate
the handle until the '0' aligns with
the 100 lb·ft line.
• Tighten the Lock Nut:
After setting the desired torque,
securely tighten the lock nut. This
step is crucial to lock the torque
value in place.
• Attach the Socket:
Place your socket onto the torque
wrench.
• Position Over Lug Nut:
Align the wrench with the lug nut.
• Grip and Tighten:
Grasp the handle and tighten the lug
nut. Apply consistent pressure until
you hear a distinct click sound.
• Click
Indicates
Achieved
Torque:
The audible click signifies that the
required torque has been reached.
This ensures precision and accuracy
in your tightening process.
5. Angle gauge
Torque-angle is commonly used
for tightening cylinder heads,
connecting rods, crankshafts, and
other
components
that
need
accurate tightening.
6. Dial and bore gauge
Dial bore gauges are mostly used
by machinists to measure the inner
diameter of bores in motor engines.
The speed and accuracy of a dial
bore gauge can save a lot of time
when used to measure cuts or hole
sizes in home remodeling projects.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
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Arlone P. Fabillaran
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7. Vernier caliper
Vernier Calliper considered one of
the precise measuring tool which
is use to the car mechanics shops
because of its accuracy. Car
technician
also use
Vernier
calliper when they are repairing
a car and have to change a part for
which the need it’s measurement.
It has got two different jaws to
measure
outside
and
inside
dimensions of an object. It can be a
scale, dial or digital type Vernier
calliper.
Diagram of Vernier calipers.
The labeled parts are
1. Outside large jaws: used to measure
external diameter or width of an object
2. Inside small jaws: used to measure
internal diameter of an object
3. Depth probe/rod: used to measure
depths of an object or a hole
4. Main scale (Metric): scale marked every
mm
5. Main scale (Imperial): scale marked in
inches and fractions
6. Vernier
scale
(Metric):
gives
interpolated measurements to 0.1mm or
better.
7. Vernier
scale
(Imperial):
gives
interpolated measurements in fractions
of an inch
8. Retainer: used to block movable part to
allow the easy transferring of a
measurement
8. Micrometer and stand
Micrometer are highly accurate
measuring instruments used to
measure the dimensions of small
parts, such as their thickness or
diameter.
A micrometre consists of a rod
graduated to measure to the
thousandth of a millimetre, or
micrometre (unit of measurement),
and a fine thread that allows you to
adjust the distance between the tips.
Where car garages are concerned,
these instruments allow for work
processes to be improved – when
used along with power tools – such
as measuring internal engine parts.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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9. Pullers and installers
Puller is a tool that is used to
remove
components
such
as
bearings, pulleys, and gears from a
shaft. These are used by mechanics
to disassemble components for
repairs, updates, and other reasons.
10.
Special
tool
based
on
manufacturer’s standards
also known as automotive specialty
tools or automotive diagnostic tools,
are specialized equipment designed
to assist mechanics, technicians,
and car enthusiasts in performing
specific tasks related to automobile
maintenance,
repair,
and
diagnostics.
11. Compression tester
0
An engine compression test is part of
basic engine diagnostics and can
help verify a blown head gasket, a
sticking
or
bent
valve,
a
flat camshaft or bad lifter, or even a
bad timing chain. A compression
test is done through the spark plug
port in each cylinder head to check
the overall pressure inside the
chamber.
12. Ridge reamer
Reamer removes ridges from top of
engine cylinders with bore diameters
3 to 5" (77 to 127mm).
Tungsten carbide cutters and finethread feed-up ensure smooth
cutting action.
Unique design lets you change from
one cylinder to another without readjusting.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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13. Valve spring compressor
A valve spring compressor apparatus
and method for compressing cylinder
valve springs for the removal and
installation of their locks or keepers
and replacement of the valve stem
seals or broken springs on an
internal combustion engine, while
the cylinder head is mounted on the
engine or supported on a work
bench.
14. Steel square
As a versatile material, steel is used
in a variety of ways in the automotive
industry. It is often used in the
chassis and body of vehicles, as well
as in the manufacturing of engine
parts. Steel is strong and durable,
making it an ideal choice for many
automotive applications
15. Mechanic stethoscope
Stethoscopes are normally found
in doctor's offices, but they can be
useful for diagnosing cars, too.
Mechanic's stethoscopes are used for
the same purpose as medical
versions: to pinpoint sounds and
listen in closely on a certain area. In
place of a chest piece sits a steel rod,
used to place against whatever you
think might be the source of the
noise or issue.
A mechanic's stethoscope can
be used to diagnose all sorts of
engine and drivetrain-related noises,
from faulty bearings to ticking
cylinder
heads,
to
knocking
crankshafts. Just place the tip of the
rod where you think the noise is
coming from and listen in, and you'll
be a step closer to finding the source
of your stress.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
November 2023
Diagnose and repair
intake and exhaust
system
Developed by:
Arlone P. Fabillaran
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16. V-block
V-blocks come in different sizes and
configurations
to
accommodate
various work piece dimensions and
requirements. Some V-blocks may
have additional features such as
clamps,
adjustable
angles,
or
magnetic
bases
for
enhanced
versatility and ease of use.
Overall, V-blocks are valuable tools
in
precision
machining
and
toolmaking, providing a stable and
reliable means of holding, aligning,
and inspecting cylindrical or round
workpieces
EQUIPMENT
1. Engine hydraulic crane
Hydraulic
engine
cranes
are used by mechanics to remove
engines from vehicles. The cranes
can lift engines of varying sizes, and
weights and come with different
settings to hoist the engine from and
back into the vehicle.
2. Chain blocks
Chain blocks are portable devices
used to manually raise or lower a
load. Chain hoists are designed for
lifting and material handling tasks.
They can raise and lower loads via
the user pulling up or down on the
hand chain. There is a wide range of
chain blocks available and they
come in various capacities and
heights for lifting.
Automotive Servicing
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Date Developed:
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3. Engine Stand
An engine stand is used to support
an engine so that it can be repaired
and examined outside a vehicle. It is
possible to work on an engine
without an engine stand, but a stand
supports the engine at a comfortable
height and allows it to be rotated to
access the top and underside.
Engine stands are on wheels so that
the engine can be moved around the
garage.
4. Vehicle Lifter

The invention of car lifts and vehicle
lifts first came to be as a
modification of the now “primitive”
inground lift. Back then, when
mechanics or repairmen had to work
on the underside parts of an
automobile or a car, they would park
the vehicle in a ramp and do their
jobs from underneath the vehicle,
inside a pit they had dug. It was
quite an expensive solution, due to
the fact that building an inground
lift requires excavation and a slew of
constructions.
Thanks
to
technological
and
mechanical
advancements, though, we now have
a range of car lifts that serve to make
repairing vehicles much easier.
The Two Post Car Lift – As
standard equipment in automobile
repair shops, it provides mechanics
with space and clearance they need
to work faster. It eases oil changing,
wiring installation, and exhaust
system jobs. These lifts also allow
different weight capacities; from
7,000 to as much as 19,000 lbs.
The Two Post Car Lif
The Four Post Car Lift
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The Four Post Car Lift – Favored by
most mechanics and dedicated car
enthusiasts, these enable complex
maintenance work. It also betters
operational safety with the highest
quality in materials and building
technology, such as a built-in
automatic lock system and ramps
with anti-skid marks. These lifts are
best applicable to wheel alignment
procedures. Its hoisting range
enables the necessary clearance for
brake repairs.
5. Crocodile jack
The jack is one of the automotive
equipment used to jack a car or lift
the car body. The jack is one of the
mandatory equipment that car
owners must have.
Jacks are commonly used to help
the car service process, check the
car's bottom, and wash the car. Jack
is also a tool that can help you in
emergencies, such as when you need
to replace a flat tire with a spare tire.
The crocodile jack is one type of
jack with a very large size, so it is
pretty heavy. Owners of this type of
jack are very rare in Indonesia. Most
of the owners are only authorized car
repair shops.
Not only large, but this jack also has
a high price. The crocodile jack also
uses hydraulic technology to lift
weights, so it's very safe to use even
for large cars.
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6. Jack Stand
A jack stand is a mechanical
device used to support a vehicle after
it has been lifted by a jack. The
purpose of a jack stand is to provide
a stable and secure platform to keep
the vehicle lifted in the air,
preventing it from falling or tipping
over.
How to use the jack stand?
To use a jack stand, you should
first park your vehicle on a flat
surface and engage the parking
brake. Then, using a hydraulic jack
or a scissor jack, lift the vehicle at
the designated lifting points as
specified in your vehicle's owner's
manual. Once the vehicle is lifted to
the desired height, place the jack
stand underneath the vehicle at a
secure location, such as the vehicle's
frame or reinforced jacking points.
To ensure maximum safety, adjust
the jack stands' height so that it is
at the same height as the vehicle's
lifting point. Then, lower the vehicle
onto the jack stand and ensure that
it is securely positioned on the
stand. It's important to note that
jack stands should always be used
in pairs, with one stand placed on
either side of the vehicle to distribute
the weight evenly.
Once the vehicle is resting
securely on the jack stands, you can
safely perform maintenance or
repair work on the vehicle. When
you're finished, carefully lower the
vehicle back down onto the ground,
remove the jack stands, and then
lower the vehicle back down to the
ground using the jack.
Automotive Servicing
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Date Developed:
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7. Press Machine
Also known as a forming press, a
machine press is a tool used in the
manufacturing industry to deform a
work piece under high pressure.
There are different types of machine
presses, including press brakes,
punch presses, shop presses, and
more.
8. Honing
Honing – sometimes confused with
lapping or grinding – creates the
optimum finish for numerous
important automotive components,
from brake drums and engine blocks
to drive shafts and anti-roll bars.
The
process
eliminates
imperfections on metal surfaces,
helping to achieve more precise
geometric tolerances.
9. Valve grinder
This machine is special for grinding
the valves in internal combustion
engines (the valves in engines on
automobiles and tractors), featuring
small size, flexible and easy
operation.
10. Valve refacer
valve refacer is mainly used to
perform a valve job, and they are
used to grind valves with an angleadjustment range from 0 to 90. The
machine is simple to deal with,
eliminates
time-consuming
operations and performs smooth
operations. The machine is made
with the latest technology which
provides all features required by the
customers.
Automotive Servicing
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Date Developed:
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11. Water heater
In EV heating systems, electric water
heaters serve as a heat source (as a
substitute for engine waste heat). In
PHEVs, the use of electric water
heaters eliminates the need to run
the car's engine to obtain a working
heat source, which as a result can
contribute to better fuel economy.
12. Surface plate
Surface plates come in a wide variety
of sizes. They can be smaller than
12x12 inches, and larger than 6x12
feet.
The largest surface plates can hold
an object as a car needs concrete
foundations to support them.
The size of the surface plate can be
found on the nameplate.
13. Pressure gauge
A pressure gauge is an instrument
used to measure a liquid or gas
inside of a machine or tank. The
gauge works by reading the
force/pressure that is being applied
from the fluids inside a tank or piece
of equipment and then outputting
that measurement on a dial or digital
output.
14. Bench vise
It is used to hold a specific thing to
perform different tasks, such as
gluing, filing, sawing, or pounding.
Sawing is performed in carpentry. A
bench vice is used when you use a
saw to cut metal or wood. A heavy
duty bench vice is used to grip the
material effectively when you cut the
object.
Automotive Servicing
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15. Bench grinder with a steel
brush
Bench grinders, which are
sometimes referred to as offhand or
pedestal grinders, are a common
piece of equipment on job sites and
in the shop. They are used for a
variety
of
tasks,
including
sharpening, polishing, buffing, and
cleaning metal objects.
16. Wash Basin
The wash bay collects all the crud
from the vehicles or equipment that
is washed there. Floor drains need
regular cleaning and maintenance to
prevent environmental and health
hazards.
17. Parts tray
Automotive parts trays have a high
technical component as they have to
ensure maximum protection of the
parts while maximising the number
of parts per container, by optimising
transport costs.
18. Overhauling table
The function of Engine and
Transmission Teardown Table is to
store and collect entire liquids, oils
and lubricants during painting,
coloring, polishing and repairing the
vehicle. The equipment is ideal to
organize the way of working on the
vehicle. The table assures user
friendliness and environment safety
as it is clean and clutter free to work
with the equipment.
Automotive Servicing
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Date Developed:
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19. Trolley
In the automotive industry, material
handling trollies are required for
various purpose, they are used
for handling components within
plants
or
departments.
Transportation of components from
one industry to another industry.
20. Oil bucket
Base oils are used to manufacture
products
including
lubricating
greases, motor oil and metal
processing fluids. Different products
require different compositions and
properties in the oil. One of the most
important factors is the liquid's
viscosity at various temperatures.
21. Hydraulic Press
The main use is in the manufacture
of car parts. They can use hydraulic
presses to manufacture large parts
such as body panels and brake pads
as well as smaller parts such a
clutches and even more complex
auto parts. What's more, the
manufacturers can use them to
assemble the parts for automobiles,
too.
MATERIALS
1. Rags
Mechanics
rags
are
indispensable in many industries
and are regularly used in automotive
garages, maintenance workshops,
manufacturing, and production.
Wherever a mechanic works, there is
inevitably a need to remove dirt
residue and grime, wick up liquids,
and wipe away solvents or oils.
2. Degreaser
A degreaser is a cleaner designed
to remove grease, oils, cutting fluids,
corrosion inhibitors, handling soils,
Automotive Servicing
(Engine Repair) NC II
Date Developed:
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fingerprints,
and
other
contamination common in assembly,
stamping
and
other
metal
fabrication in refineries, motor repair
shops, airplane hangars, and
factories, etc. Degreasers go by a
number of different names including
precision
cleaner,
maintenance
cleaner, as well as several specific for
automotive repair such as carb
cleaner or brake cleaner.
3. Engine Oil
Motor oil, engine oil, or engine
lubricant is any one of various
substances used for the lubrication
of internal combustion engines. They
typically consist of base oils
enhanced with various additives,
particularly
antiwear
additives,
detergents, dispersants, and, for
multi-grade oils, viscosity index
improvers.
4. Penetrating oil
The most common use of penetrating
oil is to loosen items like bolts and
screws that have frozen, seized up,
or become corroded over time. The
oil has a low viscosity that lets it
quickly penetrate crevices, grooves,
and pores located on a component of
a car, bicycle, or another item that
has moving parts.
There are three typical types of
penetrating oils:
• Synthetic Penetrating Oils
• Water Soluble/Emulsion Fluids
• Micro Dispersant Penetration Oils
5. Plastigauge
Plastigauge provides a simple and
effective
method
for
the
measurement
of
clearance
(separation) between fitted or hidden
surfaces. It is particularly useful for
measuring clearances in split
Automotive Servicing
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bearings, or in situations where a
feeler gauge cannot be inserted.
6. Valve lap
valve lapping refers to the procedure
that is used when the sealing
surfaces of a valve are machined to a
smooth finish with the use of a fine
abrasive. Lapping is the finishing of
a surface that has previously been
subjected to grinding.
7. Grinding compound
Valve Grinding Compound aids
valve
grinding
and
seating
operations to remove burrs, surface
defects, carbon, gum and corrosion.
This compound mixes with water to
form an easy-to-use paste and can
be used for lapping and grinding
chromium.
8. Overhauling gasket
The main function of a car gasket
is to act as an insulator between the
cylinder block and the cylinder head.
The purpose of the insulation is to
prevent oil leakage so that oil will not
enter the radiator channel or vice
versa. The presence of a car gasket
prevents oil from seeping into the
combustion chamber.
9. Adhesive and sealant
In automotive care, vehicle adhesives
and
sealants
are integral
to
upholding a car's integrity and
durability. From sealing leaks and
preventing corrosion to bonding
body panels, these products ensure
structural repair, vehicle safety and
longevity.
Automotive Servicing
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10. Sanding paper
Dry sand using 180-grit sandpaper
to
remove
rust
or
surface
damage before moving on to a 320grit paper to remove your previous
180-grit
scratches.
Whichever
method that you decide, follow it up
using 400- to 600-grit sandpaper to
sand the paint to prep the existing
paint surface for the new coatings to
be applied
11. Sealant
Automotive industry sealants
are widely used by the automotive
industry to increase the safety and
longevity of the vehicle. In addition to
preventing leakage from various
components, such as fuel tanks and
brake fluids, sealants are also used
to form a barrier between the
environment and the components.
12. Grinding stick
These grinding sticks made of
silicone
carbide provide
indispensable services in many
industry sectors, eg, in tool making,
deburring, sharpening of carving
tools and for cutting tools with
irregular shapes for which normal
grinding stones are not suitable.
13. Grocus cloth
Crocus cloth helps achieve a high
level of polish on metal jewelry,
including precious metals. It is used
like a sandpaper at first, following
coarser grits.
14. Kerosene
Kerosene is a flammable liquid
mixture of chemicals that are
produced in the distillation of crude
oil. To produce kerosene, crude oil is
distilled in a distillation tower in a
process similar to that used to
produce diesel and gasoline.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
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Self-Check of 2.1-1
PREPARING TO DIAGNOSE AND REPAIR INTAKE AND EXHAUST
SYSTEM
Identification: Identify the tools and equipment shown below. Write your
answer below the image.
1.
6.
2.
7.
3.
8.
4.
9.
5.
1o.
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ANSWER KEY 2.1-1
Identification:
1. Wheel wedge
2. Jack Stand
3. Two Post Car Lift
4. Mechanic stethoscope
5. Two Post Car Lift
6. Vacuum gauges
7. Gasket
8. Torque Wrench
9. Straight edge
10. Feeler gauge
Automotive Servicing
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Operation Sheet 1.1-2
Title:
Tools, Equipment, and Materials
Performance Objective:
Given the tools, equipment, and testing
devices, you should be able to identify and
demonstrate how to use each tool, equipment,
and material.
TOOLS:
 Torque Wrench
 Straight edge
 Feeler gauge
 Vacuum gauges
 Mechanic stethoscope
Materials:
 Rags
 Degreaser
 Penetrating oil
 Wheel wedge
 Sealant
 Gasket
Equipment:
 Vehicle Lifter
 Crocodile jack
 Jack Stand
Steps/Procedure:
1. Proceed to the Laboratory and ask for assistance from the Laboratory
Administrator.
2. Ask and acquire the complete set of Tools, materials, and equipment
together with its manual and proceed to Work Station.
3. Before starting, make sure that the working area is neat and clean
and that only the necessary materials are present.
4. Open the case of the tools and equipment, take them out one at a time
and properly scatter them in a sequential pattern or a neat order.
Automotive Servicing
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Date Developed:
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5. After arranging the set of tools, materials, and equipment, identify
each of the tools and its functions.
6. After identifying each tool and equipment, demonstrate to the trainer
the proper handling and use of each tool one at a time.
a) Torque Wrench
b) Straight edge
c) Feeler gauge
d) Vacuum gauges
e) Mechanic stethoscope
f) Rags
g) Degreaser
h) Penetrating oil
i) Wheel wedge
j) Sealant
k) Gasket
l) Vehicle Lifter
m) Crocodile jack
n) Jack Stand
Assessment Method:
Demonstration using the Performance Criteria Checklist
Automotive Servicing
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Performance Criteria Checklist 2.1-1
CRITERIA
YES
Did you….
NO
1. Proper OHS Procedure was used before the activity
2. Properly prepare the workstation and materials before
the activity
3. Properly identify each of the tools and equipment and
its function
4. Demonstrated the proper use of each hand tool
5. Properly returned the tools and equipment to its proper
storage area.
Automotive Servicing
(Engine Repair) NC II
Date Developed:
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Information Sheet 2.2-1
DIAGNOSE INTAKE AND EXHAUST SYSTEM
Learning Objectives:
After reading this INFORMATION SHEET, YOU MUST be able to
Conduct a comprehensive diagnostic analysis of the vehicle's intake and
exhaust components, pinpointing potential faults or malfunctions for efficient
and targeted repair interventions.
Introduction
In the realm of automotive maintenance and repair, a fundamental
aspect that significantly influences engine performance is the health of the
intake and exhaust systems. These systems play a crucial role in ensuring
the efficient functioning of an internal combustion engine by managing air
intake, fuel delivery, and exhaust emissions. To maintain optimal
performance, it becomes essential for automotive technicians and enthusiasts
alike to possess a thorough understanding of diagnostic analysis techniques.
This learning module delves into the intricacies of conducting a
comprehensive diagnostic analysis of a vehicle's intake and exhaust
components. By gaining insights into potential faults or malfunctions, this
knowledge empowers individuals to perform efficient and targeted repair
interventions. Whether you're a professional mechanic seeking to enhance
your skills or a DIY enthusiast eager to take control of your vehicle's wellbeing, this module will equip you with the necessary tools and know-how to
systematically identify issues, ensuring the longevity, efficiency, and
environmental compliance of your vehicle's engine.
Repair manual and books
Factory service manuals (FSM) are the manuals provided by
manufacturers that cover the servicing, maintenance, and repair of their
products. They were not originally offered to the public as they were developed
for the dealerships so that their mechanics were able to fix their products
For vehicles, the following content is usually covered: body, frame &
mounting,
engine,
suspension,
driveline,
brake
systems,
transmission/transaxle, clutch, chains, exhaust, fuel, steering, shocks,
climate control, instrumentation & Warnings Systems, battery & charging
systems, audio, lighting, electrical distribution, and wiring.
The diagram illustrated below explains the working of all the main
components of an exhaust system used in automobile. The major components
used in a typical automobile exhaust system are: exhaust manifold,
resonator, catalytic converter, exhaust pipe, muffler, tail pipe, ‘Y’ pipe, ball
Automotive Servicing
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flanges. All of these components are especially designed for providing suitable
and effective exhaust flow, silencing, and emission levels.
Exhaust
manifold
In
automotive
engineering, an exhaust manifold collects the
exhaust gases from multiple cylinders into one
pipe.
Lambda/ oxygen sensor- An oxygen sensor
(or lambda sensor) is an electronic device that
measures the proportion of oxygen (O2) in the
gas.
Catalytic converter - Catalytic Converters
are the devices used for converting toxic and
harmful hydrocarbons, carbon monoxide, and
nitrogen oxides into harmless compounds.
Resonator - Resonator installed as part of
your car or truck's exhaust system serves
one main purpose to resonate. It's sort of an
echo chamber for your car's exhaust,
preparing all of the loud noise coming from
your engine for the muffler to silence it. The
resonator doesn't just remove sound, it
changes it.
Automotive Servicing
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Silencers/muffler - A muffler (silencer in
many non-US English speaking countries) is
a device for decreasing the amount of noise
emitted by the exhaust of an internal
combustion engine
Exhaust Pipes-are explicitly engineered
to carry or transmit various toxic and
noxious gases away from the users of the
machine.
Exhaust tail pipe - The tailpipe is the last
pipe in the exhaust system. It releases the
exhaust fumes into the atmosphere beyond
the back end of the car.
Exhaust gaskets - The exhaust manifold
gasket is usually a multi-layered gasket that
contains metal and other materials that are
designed to provide the best seal possible.
As the exhaust manifold gasket is the first in
the exhaust system, it is a very important
seal that should be inspected if any problems
An exhaust flange gasket - is a round
gasket that is commonly called a donut
gasket. This gasket is often used to prevent
exhaust leaks between the cast-iron exhaust
manifold and the exhaust pipe of an
automobile or truck. It is designed with a
bevel on both sides of the gasket and a
smooth, flat inner surface. The bevelled sides
of the gasket help the gasket to seal by
allowing the clamps to form an almost circular
clamping force on the gasket's surface.
Automotive Servicing
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Date Developed:
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Analyzes the causes of engine intake and exhaust system failures
1. Air Cleaning: Failures such as cylinder scoring, supercharger damage
increased smoke, etc. are related to air quality and cleanliness.
 Dust and dirt sucked into the cylinder will damage the cylinder and
piston of the engine, as well as the valve stem, guide rod, and the blades
of the supercharger compressor. Damage to the supercharger blades
will cause the imbalance of the supercharger, in bearing damage.
 Sometimes the air filter is qualified, but the air intake line is not tightly
sealed or cracks can also cause the engine to suck dirty air.
2. Air resistance: intake resistance leads to excessive smoke exhaust and
power reduction.
 If the air resistance of the intake line is too large, the airflow will be
reduced and the air-fuel ratio will be changed, thus the engine power is
reduced, and the smoke from the engine exhaust will increase.
 In addition to visually inspecting the pipe joints whether there are
cracks or looseness, you can also use soapy water on the air-to-air
cooler, the connector, and the sealing surface of the manifold cover to
check for leaks.
3. Excessive exhaust resistance-one of the power reduction reasons.
 We can’t ignore the exhaust resistance is an important reason for the
engine power decline.
 If the exhaust flow is not smooth, the turbocharger cannot work
effectively.
 Using exhaust braking has an effect on the operation of supercharger,
so too much smoke is exhausted when using exhaust brake.
Automotive Servicing
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4. Failure of the supercharger--oil consumption and leakage:
Engine oil is used to lubricate bearings and partially cool the
supercharger. The oil is supplied to the supercharger through the oil supply
line under the working pressure of the engine. The oil returns to the engine
oil pan through the oil return pipe at the bottom of the supercharger. Seals
are used at each end of the turbocharger rotor assembly; the main function
of the sealing ring is to prevent exhaust gas or pressurized air from entering
the turbocharger housing. The possibility of oil leakage at the sealing ring is
very small, but it can also happen.
 If the pressure of the oil pan is too high, it is difficult to return the oil
from the per charger, which will increase the load on the bearing seat
and cause the oil to leak from the compressor seals.
 If the oil return pipe is blocked or damaged, it will cause the pressure
increasing of the supercharger housing, which will cause the oil to
overflow from the seals.
 If the intake or exhaust resistance is too high, a vacuum will be formed
between the compressor and supercharger housing, causing oil to leak
through the seals.
 In order to check whether there is an oil leak through the seals, remove
the exhaust pipe and the crossover pipe, and then check the turbine
housing and the crossover pipe for lubrication oil.
5. Supercharger exhaust gas actuator (bypass supercharger)-function
check.
 If the supercharger is a bypass supercharger, visually check the wear
of the rod pin, whether the hose is cracked, whether the actuator rod
and control rod are bent, etc.
 To confirm whether the bypass is working, you can do the functional
check. Connect a regulated air source and an accurate pressure gauge
to the capsule. Pressurized 180kPa, the control rod will move about
5mm.
 There should be no stuck or air leaking. If the control rod does not
move, it should be replaced.
6. Air to air Cooler-Fault reason analysis: Large resistance and leakage of air
to air cooler is one of the reasons that cause the decrease of engine power and
smoke increasing. The inspection method is as follows:
 Intercooler pressure drop check: Measure the pressure drop of the airto-air cooler system with a mercury manometer as follows: Install one
end of the manometer into the 1/8-inch pipe thread at the outlet bend
of the compressor, Install the other end of the pressure gauge to the
1/8-inch thread of the intake manifold. Running the engine at specified
higher power and corresponding speed, and recording the pressure
gauge changes. If the pressure difference is greater than 156mmHg or
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21kPa, check whether the intercooler and associated piping are
blocked, clean and replace them if necessary.
 Intercooler air leak check: install a pipe plug or cover at the intercooler
outlet, install the pressure gauge, air supply pipe, and air pressure
regulator at the cooler inlet, and apply 207kPa air pressure to the
cooler, turn off the air pressure regulator, observe the pressure gauge,
if the pressure drops is within 49kPa within 15 seconds, the cooler is
normal. If it is exceeded, then confirm whether the pressure drop is
caused by intercooler leakage or pipe joint leakage. Apply soapy water
to the pipe joint and observe whether bubbles appear.
 If it is caused by the pipe joint, repair or replace the pipe joint and
retest. If it's an intercooler leak, repeat the test three times to verify the
accuracy of the pressure drop to determine the repair or replacement of
the intercooler.
Automotive Servicing
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Information Sheet 2.3-1
REPAIR INTAKE AND EXHAUST SYSTEM
Learning Objectives:
After reading this INFORMATION SHEET, YOU MUST be able to
"Implement corrective measures for intake and exhaust components, focusing
on precision and effectiveness, to enhance overall vehicle reliability, comply
with emission standards, and extend the lifespan of engine-related parts."
Introduction
As vehicles evolve with advanced technologies, the maintenance and
repair of essential components become increasingly critical for ensuring
optimal performance, environmental compliance, and prolonged engine life.
This learning module is dedicated to empowering automotive enthusiasts and
professionals with the skills needed to implement precise and effective
corrective measures for intake and exhaust components.
The purpose of the exhaust and inlet processes is to remove the burned
gases at the end of the power stroke and admit fresh charge for the next cycle.
Indicated power of an ICE at a given speed is proportional to the mass flow
rate of air. Inducting the max air mass and retaining the mass within the
cylinder is the primary goal of the gas exchange process in engines. Engine
gas exchange processes are characterized by volumetric efficiency and it
depends on the design of engine ne subsystems such as manifolds, valves,
and ports, as well as engine operating conditions. Supercharging and
turbocharging are used to increase airflow into engine cylinder, and hence
power density.
Repair manual and books
Factory service manuals (FSM) are the manuals provided by
manufacturers that cover the servicing, maintenance, and repair of their
products. They were not originally offered to the public as they were developed
for the dealerships so that their mechanics were able to fix their products
For vehicles, the following content is usually covered: body, frame &
mounting,
engine,
suspension,
driveline,
brake
systems,
transmission/transaxle, clutch, chains, exhaust, fuel, steering, shocks,
climate control, instrumentation & Warnings Systems, battery & charging
systems, audio, lighting, electrical distribution, and wiring.
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Select tools, materials and equipment
Wrenches/spanners:
A wrench is a tool for twisting
and/or holding bolt heads or nuts
Screwdrivers
A screwdriver drives a variety of
threaded fasteners used in the
automotive industry
Standard
Tip
Screwdriver: A
slotted screw accepts a screwdriver
with a standard or blade-type tip
Phillips Screwdriver: The tip of a
Phillips screwdriver has four prongs
that fit the four slots in a Phillips
head screw
Pozidriv®
Screwdriver: The
Pozidriv screwdriver is like a Phillips
but its tip is flatter and blunter.
Pliers
Pliers are gripping tools used for
working with wires, clips, and pins.
Hammers
Hammers are identified by the material
and weight of the head. There are two
groups of hammer heads: steel and soft
faced
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Special tool required for exhaust system work
Material used on intake and exhaust system
Safety boots/ shoes
Safety boots are shoes made with a
protective reinforcement at the front
making
them
quite
durable.
The
reinforcement helps to protect the toes from
falling objects or any kind of compression.
They are normally installed with a sole plate
in the main sole to prevent against
punctures that may come from below
Exhaust gaskets - An exhaust
manifold
gasket
seals
the
connection between the manifold
and the cylinder head. This
prevents exhaust leakage out of the
connection and also ensures that
all exhaust gas will flow through
the
catalytic
converter
for
treatment.
Gloves
Gloves are personal protective equipment
(PPE) that protects the hands from the
hazards. These gloves allow digit articulation
while protecting the operator from electrical
shock, extreme heat, and ultraviolet and
infrared radiation, and also provide abrasion
resistance and enhanced grip.
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Overall
The first function of overalls is to protect.
However, they do not protect only the body of
the wearer. Overalls can be used to protect the
clothing.
Penetrating oil
Before attempting to disassemble the
exhaust system, spray all nuts and
bolts with penetrating oil
Equipment used on intake and exhaust system
Car lifter / hoist
Car Hoist, as the name indicates
that it is a type of instrument
related to or used in vehicles. The
purpose of Car Hoist is to lift up a
car into the air when someone
wants to work on it or examine
something on it that is placed
beneath the car.
Jack and Jack stands
Jack stands are tripod- or towershaped tools designed to support a
vehicle's weight when suspended.
They are positioned under the vehicle
axle or frame to provide additional
support for the elevated vehicle.
The jack stands are positioned after
you jack the vehicle up.
These stands can be used on hard
and level surfaces and for cars that are within the weight capacity of the
stands
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Multimeter
A multimeter or
a multitester,
also
known
as
a VOM
(volt-ohmmilliammeter), is an electronic measuring
instrument
that
combines
several
measurement functions in one unit. A
typical multimeter can measure voltage,
current,
and
resistance. Analog
multimeters use a microammeter with a
moving pointer to display readings. Digital
multimeters
(DMM,
DVOM) have
a
numeric display, and may also show a
graphical bar representing the measured
value. Digital multimeters have rendered
analog multimeters obsolete, because
they are now lower cost, higher precision,
and more physically robust
Exhaust gas aspirator
They
allow
sucking
the exhaust
gases directly to the source, unrolling
the hose and attaching the nozzle to
the exhaust pipe, thus avoiding that
these gases are
dispersed
in
the
environment and come into contact
with the respiratory tract of the
operators
Handscaner
An automotive scan tool (scanner) is an
electronic tool used to interface with,
diagnose and, sometimes, reprogram
vehicle
control
modules.
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Exhaust gas-analyzer
Concentrations of combustion products in
the vehicle's exhaust, most of which
pollute the air, give important diagnostic
clues to the vehicle's engine efficiency. The
component gases which contribute the
most to air pollution are hydrocarbons
(HC), carbon monoxide (CO) and oxides of
nitrogen (NOx).
Three of the five gases measured at the
tailpipe are regulated pollutants - HC, CO
and NOx. The remaining gases, oxygen
(O2) And carbon dioxide (CO2), while nonregulated, play a significant role as
diagnostic aids. Omitec's four gas
analyzer measures HC, CO, CO2 and O2
concentrations. The five gas analyzer adds
the measurement of NOx as well.
Air Intake and Exhaust Systems
 In SI engines, the intake system typically consists of an air filter, a
carburetor, and a throttle of fuel injectors in each intake port and intake
manifold.
 During the induction process, pressure losses occur as the mixture passes
through or by each of these components. The pressure drop depends on
engine speed, the flow resistance of the elements in the system, the crosssectional area through which the fresh charge moves, and the charge
density.
 In a CI engine intake system, the carburetor or EFI system and the throttle
plate are absent.
The exhaust system typically consists of an exhaust manifold, exhaust pipe,
often a catalytic converter or emission control, and a muffler or silencer.
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One complete four-stroke cycle requires two complete rotations of the
crankshaft (720) degrees and therefore one complete rotation of the camshaft
(360) degrees. The opening and closing of the valves are controlled by the
camshaft.



Push-rod assembly (OHV)
Single rocker-arm assembly actuated by overhead cam (OHV/OHC)
Twin rocker-arm assembly actuated by overhead cam (OHV/OHC)
Engine Breathing system includes intake and exhaust manifolds that
are carefully designed to provide uniform flow to & from all cylinders.
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Intake Manifold
 Intake manifold of throttle-body injection/carburetion engines are
designed to provide optimum flow of air-fuel mixture and to reduce the
chances of the vaporized fuel re-condensation. Intake manifold runners on
these engines have a few bends as possible.
 In port/direct injection SI engines (also Cl engines), the manifold is
designed for air flow only, so these can have larger runners and sharp
bends as these do not have to keep fuel suspended in air.
Exhaust Manifold
Exhaust manifolds are often made of cast iron because of their ability to
tolerate fast and severe temp changes. Exhaust gas temp is related to the
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engine load; when the engine works hard the exhaust manifold can run
almost red hot.
Air Cleaning and Silencing
The efficient removal of dust particles from air flowing into the engine is of
vital importance. Air cleaner also acts as a silencer for the intake system; that
is, it must suppress the engine induction noise to an acceptable level.
With small throttle openings, induction noise is generally of a high-frequency
character.
At medium to large throttle openings and especially with four-cylinder
engines, the major source of induction noise occurs at low-frequency or boom
periods, which arise from the implosion of the air and fuel charge into the
cylinder.
Air cleaners also act as flame arresters, in the event of engine backfiring
though the induction system.
Air Cleaning
Modern air cleaners incorporate at least one of the following physical methods
of filtration: sieve, impingement, and separation.
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The basic structure of an air cleaner/silencer is analogous to that of a
Helmholtz resonator because the air flowing through the main expansion
chamber and filter also communicates with an annular air cavity in which
there is a purely oscillating movement of air. If the suitable length of the inlet
tube is then matched to the large volume of the main chamber, the air cleaner
as a Helmholtz resonator can be turned to respond to an unwanted peak of
induction noise.
Intake valves are usually larger than exhaust valves: when the
intake valve is open, air fuel mixture is pushed into the cylinder by
atmospheric pressure, in case of naturally aspirated engines. Throttling in
intake valves reduces part-load efficiency.
When the exhaust valve opens, there is still a high pressure in
the engine cylinder. Hence, a smaller exhaust valve provides enough space for
the high-pressure exhaust gases to get out of the cylinder.
Some engines have 3 valves per cylinder: 2 IV and 1 EV.
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Valve Timing Diagram
Valve timing – and thus gas exchange – are regulated by a camshaft which
opens the valves by depressing them against the valve springs to discharge
the exhaust gas and to draw in the fresh gas.
Intake Valve Opening and Closing
Due to inertia effect and time required in attaining full opening, the inlet valve
is made to open earlier so that by the time the piston reaches TDC, the valve
is full open.
Engine performance is relatively insensitive to the IVO timing.
The inlet valve remains open long after the piston reaches the BDC and
changes direction into the compression stroke. This takes advantage of the
velocity of the incoming gases, helping to continue filling the cylinder with
additional air-fuel mixture even though the piston is moving back up the
cylinder.
IVC is one of the principle factors that determines the high-speed volumetric
efficiency; it also affects low speed volumetric efficiency due to back-flow into
the intake.
Exhaust Valve Opening, Closing & Overlapping
The exhaust valve must open well before the end of the power stroke. Blowdown is a term describing the part of the power stroke between when the EVO
and the piston arrive at BDC. The pressure of the expanded gases must be
bled off during the blow-down period before the piston changes direction and
moves up on the exhaust stroke.
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Most of the power of the burning gases has been delivered to the piston by
about halfway through the power stroke so opening the exhaust valve at this
point does not significantly harm an engine’s power output.
The timing of EVO affects the cycle efficiency since it determines the effective
expansion ratio.
EVC ends exhaust process and determines the duration of valve overlap
period.
At idle and light load, in SI engines, valve
overlap regulates the quantity of exhaust
gases that flow back into the combustion
chamber through the influence of intake
manifold vacuum. At high engine speeds
and loads, inertia of moving exhaust gas
leaving the cylinder results in lower
pressure behind it. This vacuum condition
sucks more exhaust from the cylinder and
helps draw more fuel-air mixture during
valve overlap, increasing power.
Variable Valve Timing & Lift
o The camshaft profile in conventional engines has always been
compromised between low and high rpm demands.
o Variable valve timing (VVT) is common in 2 basic types;
a) Varies the cam-to-crank phasing and also the lift and duration
b) Varies valve timing only
c) A combination of the two is also common.
o VTEC: Variable valve timing and lift electronic control
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VVT causes changes to duration between low and high rpm operation
Valve Timing
Exhaust Silencer
Exhaust noise arises from the
sudden release of compressed
gas travelling at a speed in the
region of 60-90 m/s, as each
exhaust valve is opened.
Exhaust silencer suppresses
this noise by breaking up the
intermittent system of high
velocity exhaust gases into
numerous small streams so
that they leave the tail pipe in
amore nearly constant flow at
low velocity.
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Information Sheet 2.4-1
COMPLETE WORK PROCESSES
Learning Objectives:
After reading this INFORMATION SHEET, YOU MUST be able to
1) Conduct a comprehensive final inspection of the repaired intake and
exhaust systems, ensuring all components are properly installed and
functioning as intended.
2) to guarantee the effectiveness of the repair work and identify any
potential issues before returning the vehicle to the customer.
3) to maintain a safe work environment and protect individuals from
hazards associated with the inspection and repair of intake and exhaust
systems.
Introduction
In the culmination of the intake and exhaust system repair process, a
pivotal stage emerges with the undertaking of a meticulous final inspection.
This critical step involves a thorough examination of the repaired components
to ascertain their proper installation and functionality, aiming to guarantee
the overall effectiveness of the repair work. Beyond mere quality assurance,
this inspection serves the paramount purpose of identifying any potential
issues that might compromise the system's performance before the vehicle is
returned to the customer. Simultaneously, a steadfast commitment to safety
is upheld during this phase, with a focus on maintaining a secure work
environment. By donning the necessary personal protective equipment (PPE),
we ensure the well-being of individuals involved in the inspection and repair
procedures, safeguarding them from potential hazards associated with the
intricate workings of intake and exhaust systems.
Safety precautions in the working area
Individual protections
The wearing of individual protection equipment (EPI) is compulsory to work
safely on any operation.
The following items of personal protective equipment are compulsory:
o Trousers/overalls or a suitable combination
o Safety shoes
Depending on the location and the type of operation, these items of individual
protection equipment are compulsory:
o Safety helmet, when operating underneath the vehicle
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o Protection goggles, when working on fluid circuits, fuel circuits, air
circuits, etc., or for operations that could involve the suspension or
projection of particles in the air
o Face masks, for operations that could involve the suspension or
projection of particles in the air
o Safety gloves, to guard against cuts or exposure to chemical products
o Ear protection, when working in a noisy environment
All these items of individual protection equipment are available in your Parts
shop.
Place a protective cover on the following:
o Front wings
o Driver's seat
o Floor carpet (driver's side)
o The steering wheels
Working area
The working area should be clean and
tidy.
Environment
Respect the environmental regulations:
o Separation and collection of waste
o Ejection of used water
o Air pollution
o Noise emissions
Correct Testing
Exhaust Gas Analyzers is widely appreciated by its accurate measurements,
optimum functionality and long service life. Gas analyzer test visualizes
measurement data graphically. This technologically advanced Exhaust Gas
Analyzers are highly sought after for significant parameters including
adequate heat provision, low energy consumption and reduced pollutant
emissions. The highly efficient arrays of Analyzers are provided by us at cost
effective prices
We break down our analyzers into 5 categories:
o Oxygen or O2 Analyzers with a range from 0-100% O2 Handheld, Panel
Mount, Visual and Audible Alarms, Optional Relay Switch on Alarm
model
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o Carbon Monoxide or CO Analyzers with a range from 0-100 ppm CO
Handheld, Panel Mount, Visual and Audible Alarms, Optional Relay
Switch on Alarm model
o Carbon Dioxide or CO2 Analyzers with a switchable range from 02000ppm CO2 Handheld, Panel Mount, Visual and Audible Alarms,
Optional Relay Switch on Alarm model
o Helium or He Analyzers with a range of 0-100% He Concentration
Handheld, Panel Mount, Visual and Audible Alarms, Optional Relay
Switch on Alarm model
o Trimix Analyzers capable of monitoring the composition of:
Helium in Nitrogen (N2) and/or Oxygen (O2) Oxygen in Nitrogen (N2) and/or
Helium (He)
This technique can therefore reveal cyclical variation, as well as cylinder-tocylinder variation. Such a capability may also be useful when verifying the
effects of variable valve timing.
Test Lambda closed loop control
The O2 or Oxygen sensor works like a tiny voltage generator. It actually
produces a voltage in the theoretical range of 0.01 to 0.98 volts. It does this
depending on the Oxygen content of the exhaust. This signal is a major input
to the ECM, which it uses to control the air-fuel mixture and emissions.
Theorxy of Operation
The O2 sensor measures the oxygen content of the exhaust. The O2 sensor’s
sensing ability comes about by producing a small voltage proportionate to
the exhaust oxygen content. In other words, if the oxygen content is low it
produces a high voltage (0.90 Volts - Rich mixture) and if the oxygen content
is high it produces a low voltage (0.10 Volts - Lean mixture). Although
theoretically the O2 sensor should cycle between 0.00 volts and 1.00 volts,
in reality it cycles between 0.10 volts and 0.90 volts.
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In many modern cars the O2 sensor has been replaced by the AFR or
Wide-Band sensor. But, the rear or after-cat O2 sensor is still the same
old fashioned O2 sensor.
A few key issues are very important in the analysis of O2 sensor
signals.
o
o
An O2 sensor will cycle between 0.10 to 0.90 or almost 1 volt.
o
An O2 sensor has to reach the 0.8x Volts amplitude mark while at full
operation.
An O2 sensor also has to reach the 0.1x Volts amplitude mark while at
full operation.
(Full operation means the engine is fully warmed up, O2 sensor above the
600 deg. F. operating temperature, and no fuel or mechanical problems
present. Also most rear O2 sensor will not cycle as wide, but during testing
you have to goose the throttle and do a few WOT events to prove your O2
sensor voltage swing.)
o
o
The front O2 sensor must cycle at least once per second, which would
show 3 cross counts on the scan tool PID.
o
Silicone is the leading cause of O2 contamination.
o
It is easier for an O2 sensor to go from rich to lean than vise-versa.
o
O2 sensors tend to fail on rich bias. In other words, they tend to shift
their cycling to the upper side or rich side of the voltage scale.
o
There is a small hole at the body of the O2 sensor, which allows it sample
the outside reference Oxygen.
o
Contrary to what many people think, an O2 sensor WILL NOT cycle by
itself. The O2 sensor cycle is a direct result of the ECM response to the
changes in the mixture.
o
When the O2 cycles and crosses the 0.450 volts mark every second, the
system is in CLOSE- LOOP.
o
Even though an O2 sensor is cycling and crossing 0.450 volts (ECM in
close loop) it DOES NOT mean that it is working properly.
o
O2 sensor operation is extremely important not only to keep HC & CO
emissions low but also to reduce NOx as well.
o
Proper O2 sensor cycling will determine the catalytic converter’s
efficiency. The catalytic converter needs the O2 sensor cycling at its
proper amplitude and frequency for it to function at its maximum
efficiency.
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o
An O2 sensor with a high voltage reading does not necessarily mean that
the mixture is rich or high in fuel content. An EGR valve problem will
send the O2 signal high as well.
o
The O2 sensor signal stuck at 450 mV is an indication of an open O2
sensor circuit (signal wire) or faulty O2 signal ground. The 450 mV value
is called a bias voltage and it is not the same for all manufacturers. Some
manufacturers employ a dedicated O2 sensor ground. Such a ground
lead is attached to the engine block or chassis and feeds an ECM O2
ground pin only. The O2 circuit is then grounded through the inside of
the ECM electronic board by this ground wire. A loss of this ground
would also put the O2 sensor signal at around 450 mV, which makes it
look like an open circuit. The same holds true for Chrysler, but these use
a different O2 bias voltage, which is usually 2.00 to 4.00 volts.
Remember, this bias voltage circuit has very low current.
Take the car for a test drive
Whether you replaced your exhaust due to damage or decided to upgrade it for
performance, remember to always take caution when driving through driveways,
speed bumps, and dips. The exhaust is exposed underneath the car and can be
damaged if pulling into a driveway too quickly.
If you live in areas that experience snow, be sure to have your undercarriage
washed weekly during those winter months to prevent your exhaust and other
components under the vehicle exposed to the elements from turning to rust.
If you aren’t comfortable replacing your car’s exhaust system yourself, ask a
professional mechanic, such as one from your mechanic, to help you replace your
hangers, manifold gasket, or catalytic converter. Our mobile mechanics come to your
home or office to inspect or repair your car at your convenience.
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Date Developed:
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