Engine Management – V6 – Service Operations Page 6C1-3–39
Disassemble
Do not use a sharp implement such as a knife
to cut the ignition coil boot (1) from the
ignition coil. Using a sharp implement may
damage the ignition coil insulator (2).
1 Using your thumb, work the ignition coil boot off the ignition coil insulator.
NOTE
Take care the spring (3) does not become
dislodged as the boot is removed.
To aid removal of the boot, use a blunt
instrument to lift the boot edge away from the
coil insulator and spray a release agent between
the boot and the coil insulator.
2 Remove the spring from the ignition coil insulator.
Figure 6C1-3 – 51
Reassemble
1 Position the spring (3) in the insulator recess, refer to Figure 6C1-3 – 51.
2 Lubricate the ignition coil insulator (1) with talcum powder.
3 Fit the ignition coil boot, ensuring it is fully seated at the top of the insulator.
Figure 6C1-3 – 52
Test
Never probe the ignition coil with a 12 V tester
as the ignition coil will be damaged.
Due to the internal components of the ignition coil assembly, it is not possible to perform any primary and / or secondary
resistance checks. For further information on the ignition coil operation, refer to 6C1-1 Engine Management – V6 –
General Information.
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Engine Management – V6 – Service Operations Page 6C1-3–40
Reinstall
Reinstallation of the ignition coil is the reverse of the removal procedure, noting the following:
1 Lubricate the ignition coil sealing rubber (1) with clean engine oil, and the inside of the ignition coil boot (2)
with talcum powder.
Figure 6C1-3 – 53
2 Reinstall the ignition coil by pushing down on the ignition coil to engage the sealing rubber in the camshaft cover.
Ensure the ignition coil is fully seated before
tightening the attaching bolt to the specified
torque.
3 Reinstall the ignition coil bolt and tighten to the correct torque specification. Ignition coil attaching bolt
torque specification ...................................7.0 – 11.0 Nm
4 Road test the vehicle and check for correct operation.
2.16 Intake Air Duct Assembly
Remove
1 Turn the ignition switch off.
2 Disconnect the crankcase ventilation hose (1) from the air intake duct (2).
3 Loosen the two air intake duct retaining clamps (3),
4 Pull the air intake duct away from the throttle body.
5 Pull the air intake duct away from the mass air flow sensor.
Figure 6C1-3 – 54
Reinstall
Reinstallation of the air intake duct is the reverse of the removal procedure, noting the following:
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Engine Management – V6 – Service Operations Page 6C1-3–43
6 Remove the bolt (1) attaching the knock sensor (2) to
the engine block and remove the knock sensor.
Figure 6C1-3 – 57
Reinstall
Reinstallation of the knock sensor is the reverse of the removal procedure, noting the following:
1 Ensure the knock sensor mounting surface is flat and free of any dirt, oxidisation, etc.
Ensure the knock sensor is fully seated and
correctly aligned before tightening the
attaching bolt.
Do not over-tighten the attaching bolt as
incorrect operation of the knock sensor may
result.
2 Reinstall the knock sensor and bolt (1). Align the knock sensor so that it is parallel to the engine oil pan
mounting surface (2), ± 3° (3).
3 Tighten the knock sensor bolt to the correct torque specification.
Knock sensor attaching bolt
torque specification .................................21.0 – 25.0 Nm
4 Road test the vehicle and check for correct operation, taking particular note that no exhaust leaks are
evident.
Figure 6C1-3 – 58
2.19 Knock Sensor, Bank 1 (RHS)
Remove
1 Turn the ignition switch off.
2 Raise the front of the vehicle and support on safety stands, refer to 0A General Information for location of the jacking points.
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Engine Management – V6 – Service Operations Page 6C1-3–45
Ensure the knock sensor is fully seated
before tightening the attaching bolt.
Do not over-tighten the attaching bolt as
incorrect operation of the knock sensor may
result.
2 Reinstall the knock sensor and bolt (1). Align the knock sensor so that it is parallel to the engine oil pan
mounting surface (2), ± 3° (3).
3 Tighten the knock sensor bolt to the correct torque specification.
Knock sensor attaching bolt
torque specification .................................21.0 – 25.0 Nm
4 Road test the vehicle and check for correct operation.
Figure 6C1-3 – 61
2.20 Mass Air Flow Sensor
The intake air temperature (IAT) sensor is part of the mass air flow (MAF) Sensor. For the IAT sensor test procedure
refer to 2.17 Intake Air Temperature Sensor.
Handling Precautions
Under no circumstances should the MAF
sensor retaining screws (1) be loosened or
removed as the MAF will become
unserviceable and will require replacement.
Figure 6C1-3 – 62
Remove
1 Turn the ignition switch off.
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Engine Management – V6 – Service Operations Page 6C1-3–48
2.22 Spark Plugs
Service Precautions
1 Allow the engine to cool (to at least 50°C) before attempting to remove spark plugs. Attempting to remove spark
plugs from a hot engine may cause the plug / cylinder head threads to bind, resulting in tearing of the alloy cylinder
head threads.
2 Clean the spark plug recess area before removing any spark plug. Failure to do so could result in engine damage because of dirt or other foreign material entering the cylinder head or by the contamination of the cylinder head
threads. The contaminated threads may then prevent the correct seating of the new or replaced plug. If required,
use a thread chaser to clean the threads of any contamination where this is suspected.
3 Under no circumstances should the spark plug/s gap be adjusted. If the gap is not within specifications,
replace the spark plug.
Figure 6C1-3 – 66
Remove
1 Turn the ignition switch off.
2 Remove the ignition coil/s, refer to 2.15 Ignition Coil.
3 Using a suitable spark plug socket, loosen the spark plug slightly and then re-tighten to break away any carbon deposits on the threads.
Wear eye protection to avoid injury.
4 Loosen the spark plug once again one or two turns, then use compressed air to remove any foreign material that may otherwise enter the combustion chamber.
5 Remove the spark plug (1).
6 Repeat as required for the remaining spark plugs.
NOTE
Place each spark plug in the same order as that
of removal. This will enable any abnormal spark
plug condition to be identified with the cylinder.
NOTE
If the spark plugs are removed for an indefinite
period before installation, plug the spark plug
openings to prevent foreign particle ingress.
7 Repeat steps 2 to 5 for the remaining spark plugs as required.
Figure 6C1-3 – 67
Inspect
The spark plugs must not be re-gapped. If the gap of a spark plug is outside the specified range, replace the spark plug.
In addition, replace spark plugs that shows excessive dirt deposit or broken insulators.
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Engine Management – V6 – Service Operations Page 6C1-3–50
• plug/s overheating due to insufficient tightening (caused by combustion gases leaking past the threads).
Broken Insulator
Broken insulators are usually the result of improper installation or carelessness.
Breaks in the upper insulator can result from a poor fitting spark plug socket or impact. The cracked insulator may not
show up until oil or moisture penetrates the crack. The crack is often just below the crimped part of the shell and may not
be visible.
Breaks in the lower insulator often result from careless re-gapping and are usually visible.
This can also result from the plug operating too hot. For example, in periods of high speed operation or under heavy
loads.
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Engine Management – V6 – Service Operations Page 6C1-3–51
Analysis of Spark Plug Condition
Figure 6C1-3 – 69
Legend
1 Normal
2 Carbon Fouled
3 Oil Fouled
4 Deposit Fouling A 5 Deposit Fouling B
6 Deposit Fouling C
7 Detonation
8 Pre-ignition 9 Heat Shock Failure
10 Insufficient Installation Torque
Normal Operation (1)
Brown or greyish-tan deposits and slight electrode wear indicate correct spark plug heat range and mixed periods of high
and low speed driving.
Carbon Fouled (2)
Dry, fluffy black carbon deposits possibly due to poor ignition output, a weak coil, excessive idling or slow speeds under
light load. If spark plug temperatures remain too low for normal combustion, the deposits are not burned off.
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Engine Management – V6 – Service Operations Page 6C1-3–52
Oil Fouled (3)
W et, oily deposits with minor electrode wear possibly due to oil leaking past worn piston rings.
Breaking in a new or recently overhauled engine before the rings are fully seated may also result in this condition.
Deposit Fouling A (4)
Red brown, yellow and white coloured coatings on the insulator tip which are by-products of combustion. They come
from fuel and lubricating oil which generally contain additives. Most powdery deposits have no adverse effect on spark
plug operation, however, they may cause intermittent missing under severe operating conditions.
Deposit Fouling B (5)
Deposits similar to those identified in deposit fouling A (4). These are also by-products of combustion from fuel and
lubricating oil. Excessive valve stem clearances and / or defective intake valve seals allow too much oil to enter the
combustion chamber. The deposits will accumulate on the portion of the spark plug that projects into the chamber and
will be heaviest on the side facing the intake valve. If this condition is only detected in one or two cylinders, check the
valve stem seals.
Deposit Fouling C (6)
Most powdery deposits identified in deposit fouling A (4) have no adverse effect on the operation of the spark plug as
long as they remain powdery.
Under certain conditions of operation however, these deposits melt and form a shiny glaze coating on the insulator.
W hen hot, this acts as a good electrical conductor allowing the current to flow along the deposit instead of sparking
across the gap.
Detonation (7)
Commonly referred to as engine knock or pinging, detonation causes severe shocks inside the combustion chamber
causing damage to parts.
Pre-ignition (8)
Burnt or blistered insulator tip and badly eroded electrodes probably due to the excessive heat.
This is often caused by a cooling system blockage, sticking valves, improperly installed spark plugs or plugs that are the
wrong heat rating (too hot).
Sustained high speed with a heavy load can produce temperatures high enough to cause pre-ignition.
Heat Shock Failure (9)
A rapid increase in spark plug tip temperature under severe operating conditions can cause heat shock and result in
fractured insulators. This is a common cause of broken and cracked insulator tips.
Insufficient Installation Torque (10)
Poor contact between the spark plug and the cylinder head seat.
The lack of proper heat transfer that results from poor seat contact causes overheating of the spark plug. In many cases,
severe damage occurs. Dirty threads in the cylinder head can cause the plug to seize before it is seated.
Ensure the cylinder head and spark plug threads are free of deposits, burrs and scale before installation.
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