Chapter 10
Engine
Disassembly and Cleaning
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duplicated, or posted to a publicly accessible website, in whole or in part.
Engine Removal Tips
• Clean before beginning removal
• Have the tools and equipment before you
begin
• Always follow removal procedures
• Adhere to all safety guidelines
• Use a digital camera or camcorder to record
various locations and connections
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duplicated, or posted to a publicly accessible website, in whole or in part.
General Removal Procedures
•
•
•
•
Install a battery memory saver
Remove hood and place in safe place
Drain fluids and remove oil filter
Disconnect linkages and electrical
connections, label as necessary
• Remove air intake components
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duplicated, or posted to a publicly accessible website, in whole or in part.
Labeling For Reassembly
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General Removal Procedures (Cont.)
• Disconnect and close off fuel lines
• Label and disconnect vacuum lines
• Remove drive belts and set power steering
pump and air conditioning compressor aside
• Disconnect heater and radiator hoses
• Disconnect exhaust pipe
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duplicated, or posted to a publicly accessible website, in whole or in part.
FWD Engine Removal
• Many FWD vehicles require the engine and
transmission to be removed together as an
assembly
• Some FWD engines can be remove from
above
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duplicated, or posted to a publicly accessible website, in whole or in part.
FWD Engine Removal (Cont.)
• A transaxle support is necessary if the engine
is removed from above
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duplicated, or posted to a publicly accessible website, in whole or in part.
FWD Engine Removal (Cont.)
• Remove the axle shafts from the transaxle
• Axles can usually be pried away from transaxle
once the steering knuckle is separated from
the lower control arm
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duplicated, or posted to a publicly accessible website, in whole or in part.
FWD Engine Removal (Cont.)
• If possible, leave
axles attached to
hub assemblies
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duplicated, or posted to a publicly accessible website, in whole or in part.
RWD Engine Removal
• The engine is usually removed from above
through the hood opening
• After all connections and components are
removed, separate the engine from the
transmission
• Remove motor mount connections and
remove the engine
• Always support the transmission
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duplicated, or posted to a publicly accessible website, in whole or in part.
Engine Preparation
• Once removed,
mount securely to
an engine stand
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duplicated, or posted to a publicly accessible website, in whole or in part.
Engine Preparation (Cont.)
• Slowly disassemble and
visually inspect the
parts
• Look for excessive wear
on moving parts
• Always follow the
service procedures for
proper disassembly and
cleaning
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duplicated, or posted to a publicly accessible website, in whole or in part.
Cylinder Head Removal
• Remove the intake
and exhaust manifolds
• Remove the valve
cover or covers
• Inspect for sludge
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duplicated, or posted to a publicly accessible website, in whole or in part.
Cylinder Head Removal (Cont.)
• Disassemble rocker
arm components
• On OHC engines align
timing marks and
remove the timing
belt
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duplicated, or posted to a publicly accessible website, in whole or in part.
Cylinder Head Removal (Cont.)
• Keep all pushrods and rocker arm assemblies
in exact order
• Loosen cylinder head bolts one or two turns
following the detorque sequence – often the
reverse of the torque sequence
• Inspect and save the head gasket
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duplicated, or posted to a publicly accessible website, in whole or in part.
Detorque Example
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Knowledge Check
• Why should cylinder heads bolts be loosened
in reverse of the torque sequence?
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duplicated, or posted to a publicly accessible website, in whole or in part.
Cleaning Engine Parts
• After disassembly, parts should be thoroughly
inspected and cleaned
• The cleaning method depends on the
component and the equipment available
• Incorrect cleaning methods or agents can
harm or destroy engine parts
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duplicated, or posted to a publicly accessible website, in whole or in part.
Types of Soil Contaminants
• Water-Soluble Soils
– Include dirt, dust, and mud
• Organic Soils
– Examples are oil, grease, and carbon
• Rust
– Results from a chemical reaction when iron and steel are
exposed to oxygen and moisture
• Scale
– Results from minerals that have separated from water
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duplicated, or posted to a publicly accessible website, in whole or in part.
Three Basic Cleaning Processes
• Chemical Cleaning
– Uses a chemical reaction
• Thermal Cleaning
– Relies on heat to bake off soil
• Abrasive Cleaners
– Are usually used in conjunction with other
cleaning processes
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duplicated, or posted to a publicly accessible website, in whole or in part.
Chemical Cleaning
• Used to remove dirt, grease, scale, paint,
and/or rust
• Always wear the proper PPE when working
with chemical cleaning agents
• Hydrocarbon solvents require special handling
and disposal
• Some cleaners are water-based
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duplicated, or posted to a publicly accessible website, in whole or in part.
Chemical Cleaning Machines
• Parts washers are commonly used and can
soak, agitate, stream, and spray clean
• Hot or cold soak tanks immerse components
in cleaning solution to remove grease
• Hot spray tanks use pressurized spray to
decrease cleaning times
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duplicated, or posted to a publicly accessible website, in whole or in part.
Parts Cleaning Tank
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duplicated, or posted to a publicly accessible website, in whole or in part.
Thermal Cleaning
• Uses heat to bake off or oxidize dirt and other
contaminates
• Becoming more popular because of reduced
amount of hazardous wastes
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duplicated, or posted to a publicly accessible website, in whole or in part.
Abrasive Cleaners
• Used in conjunction with other cleaning
equipment
• Shot and grit blasters used on parts that will
later be machined
• Parts tumblers used on small parts
• Vibration cleaners or shakers use vibrating tub
with abrasives to scrub parts
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duplicated, or posted to a publicly accessible website, in whole or in part.
Alternative Cleaning Methods
• Ultrasonic cleaners uses high-frequency sound
waves to clean parts
• Citrus chemicals are safer to handle and easier
to dispose of
• Salt baths use high-temperature molten salt to
dissolve carbon, grease, oil, dirt, paint, and
some gasket materials
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duplicated, or posted to a publicly accessible website, in whole or in part.
Knowledge Check
• Which type of engine cleaning has become
the most popular and why?
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duplicated, or posted to a publicly accessible website, in whole or in part.
Crack Detection
• Cleaned engine parts should be carefully
inspected
• Cracks result from pressure or temperature
changes, fatigue from stress cycles, impact
damage, and engine overheating
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duplicated, or posted to a publicly accessible website, in whole or in part.
Cracked Lifter Bore
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Crack Detection Methods
• Blocks and heads can be pressurized with air
and placed into a water tank
• Magnetic particle inspection magnetizes the
metal
• Dye penetrants are sprayed or brushed on the
surface and when dry show cracks
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duplicated, or posted to a publicly accessible website, in whole or in part.
Magnetic Detection
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Dye Detection
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In-Vehicle Engine Service
• Oil pan gasket replacement
• Vibration damper replacement
• Cylinder head replacement
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duplicated, or posted to a publicly accessible website, in whole or in part.