2007 ISUZU KB P190 battery

Engine Mechanical – V6 Page 6A1–38

2.15 Engine Compression Test
A compression pressure test of the engine cylinders determines the condition of the rings, the valves and the head
gasket.
Preliminary Steps
1 Ensure the battery is fully charged.
2 Remove the spark plugs from all cylinders, refer to 6C1-3 Engine Management – V6 – Service Operations.
NOTE
DTCs will set when the fuel system or the ignition
system is disabled and the engine is cranked.
Disregard DTCs that set under this condition.
3 Disable the fuel system by removing the fuel pump relay, refer to 8A Electrical Body & Chassis.
4 Start the engine to use any residual fuel from the fuel lines.
4 Disable the ignition coils by removing fuses 34 and 35, refer to 8A Electrical Body & Chassis .
5 Using Tech 2, command the throttle plate to wide open throttle.
Engine Cylinder Compression Test
1 Install the compression tester to cylinder number 1.
2 W hile observing the compression tester reading, turn the ignition to the START position for several seconds and then allow the ignition to return to the ON position.
3 Record the highest compression reading obtained.
4 Repeat the engine compression test for each cylinder.
Test Result Evaluation
Normal engine compression pressure builds quickly and evenly to over 965 kPa. In addition, the lowest reading of an
engine cylinder should not be less than 70 percent of the highest reading. If any cylinder fails the compression test,
adding 15 ml of engine oil to the suspected cylinder may help isolate the following fault condition.
1 A fault condition in the piston rings will produce the following result:
• A low compression on the first engine cycle
• The compression tends to build-up with the succeeding engine rotation.
• The compression improves with the addition of engine oil.
2 A fault condition in an intake or exhaust valve will produce the following result:
• A low compression on the first engine cycle
• The compression does not build with the succeeding engine rotation.
• The compression does not improve with the addition of engine oil.
3 A fault condition in the cylinder head gasket will produce the following result:
• A low compression on the first engine cycle
• The compression does not build with the succeeding engine rotation.
• The compression does not improve with the addition of engine oil.
• The suspected cylinders are positioned adjacent to each other.
• The engine oil may be contaminated with engine coolant.
• The engine coolant may be contaminated with engine oil.
Once the fault has been identified, refer to the relevant service procedure and reinstall the removed components.
Using Tech 2, clear DTCs.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–39

2.16 Cylinder Leakage Test
A leakage test may be performed to measure cylinder/combustion chamber leakage. High cylinder leakage may indicate
one or more of the following:
• worn or burnt valves,
• broken valve springs,
• stuck valve lifters,
• incorrect valve lash/adjustment,
• damaged piston,
• worn piston rings,
• worn or scored cylinder bore,
• damaged cylinder head gasket,
• cracked or damaged cylinder head, or
• cracked or damaged engine block.

1 Disconnect the battery ground negative cable.
2 Remove the spark plugs from all cylinders, refer to 6C1-3 Engine Management – V6 – Service Operations.
3 Rotate the crankshaft to place the piston in the cylinder being tested at top dead centre (TDC) of the compression stroke.
4 Install a commercially available cylinder head leak down tester into the spark plug hole.
NOTE
If required, hold the crankshaft balancer bolt to
prevent the engine from rotating.
5 Apply shop air pressure to the cylinder head leak down tester and adjust according to the manufacturers instructions.
6 Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions:
• air leakage sounds at the throttle body or air inlet duct that may indicate a worn or burnt intake valve or a
broken valve spring,
• air leakage sounds at the exhaust system tailpipe that may indicate a worn or burnt exhaust valve or a broken
valve spring,
• air leakage sounds from the crankcase, oil level indicator tube, or oil fill tube that may indicate worn piston
rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block or a damaged cylinder
head, or
• air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket.
7 Perform the leakage test on the remaining cylinders and record the values.
2.17 Engine Oil Consumption Diagnosis
Definition
Excessive oil consumption (not due to leaks) is the use of 3 litres or more of engine oil within 10,000 kilometres. Prior to
performing oil pressure testing, a preliminary inspection of the vehicle should be performed. During the preliminary visual
inspection, the following likely causes of excessive oil usage should be investigated.
Cause Correction
External oil leaks. Refer to 2.18 Engine Oil Leak Diagnosis.
Incorrect oil level or reading of the oil level indicator. Check for the correct oil level, refer to 3.1 Engine Oil.
Incorrect oil viscosity. Replace the engine oil, using the recommended SAE grade
of engine oil, refer to 3.1 Engine Oil.
Continuous high-speed driving or severe usage. Service vehicle more frequently, refer to 0B Lubrication and
Service.
Crankcase ventilation system restricted or malfunctioning. Repair or replace crankcase ventilation system components as required, refer to 6C1-3 Engine Management – V6 –
Service Operations.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–57

3.3 Oil Filter Adaptor
Remove

Disconnection of the battery affects certain
vehicle electronic systems, refer to 1.1
WARNING, CAUTION and NOTES before
disconnecting the battery.
1 Disconnect the battery negative terminal.
2 Disconnect the wiring harness connector from the oil pressure sender.

3 Remove the oil filter adaptor attaching bolts (2), four places.
4 Remove the oil filter adaptor and discard the gasket (3).
5 Clean the surfaces of the adaptor and cylinder block.

• Do not use a screwdriver or similar to
prise the oil filter adapter from the engine
as damage to the sealing surface may
occur.
• If required, use a rubber mallet to tap the
oil filter adapter to loosen the
components prior to separating.
Tapping should be done at bends,
corners or reinforced areas to prevent
distortion of parts.
Figure 6A1 – 27
Reinstall
Reinstallation of the oil filter adaptor is the reverse of the removal procedure, noting the following:
1 A new gasket must be used.
2 Loosely install the oil filter adaptor attaching bolts, then tighten all fasteners to the correct torque specification.
Oil filter adaptor attaching bolt
torque specification .................................. 20.0- 26.0 Nm

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–63

Remove

Disconnection of the battery affects certain
vehicle electronic systems. Refer to 1.1
WARNING, CAUTION and NOTES before
disconnecting the battery.



1 Disconnect the battery negative terminal.
2 Remove the air intake duct (1) and hose (2), refer to 6C1-3 Engine Management – V6 – Service
Operations.

Figure 6A1 – 34

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–68

CAUTION
Tighten the intake manifold bolts in a circular
pattern starting at the centre bolt and moving
outward.
2 Ensure that all fasteners are tightened to the correct torque specification. Upper intake manifold to lower
intake manifold attaching bolt
torque specification ............................................23.0 Nm
Upper intake manifold to
cylinder head attaching bolt
torque specification ............................................23.0 Nm

Incorrect wiring connector installation may
cause component malfunction or component
damage.
3 Ensure all wiring connectors are fully engaged and if applicable, locked in place.
4 Ensure all wiring harnesses are correctly routed and attached securely in their retaining clips.
5 Ensure that all hoses and pipes are routed correctly and that any retaining clips are correctly installed.
6 Start and run the engine to check for correct operation.
3.10 Intake Manifold Assembly – Complete
The intake manifold comprises of an upper and lower section. Some service procedures only require the removal of the
upper intake manifold (e.g. fuel injector/spark plug servicing), while other service procedures require the removal of both
the upper and lower manifold as a complete assembly (e.g. cylinder head/s). If only the upper intake manifold needs to
be removed, refer to 3.9 Upper Intake Manifold.
Remove

Disconnection of the battery affects certain
vehicle electronic systems. Refer to 1.1
WARNING, CAUTION and NOTES before
disconnecting the battery.
1 Depressurise the fuel system.
2 Disconnect the battery negative terminal.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–75

CAUTION
Tighten the intake manifold bolts in a circular
pattern starting at the centre bolt and moving
outward.
4 Ensure that all fasteners are tightened to the correct torque specification. Upper intake manifold to lower intake
manifold attaching bolt torque specification .......23.0 Nm
Upper intake manifold to cylinder
head attaching bolt torque specification .............23.0 Nm
Lower intake manifold to cylinder
head attaching bolt torque specification .............23.0 Nm
Fuel injector wiring harness bracket
attaching bolt torque specification ........................9.0 Nm

Incorrect wiring connector installation may
cause component malfunction or component
damage.
5 Ensure all wiring connectors are fully engaged and if applicable, locked in place.
6 Ensure all wiring harnesses are correctly routed and attached securely in their retaining clips.
7 Ensure that all hoses and pipes are routed correctly and that any retaining clips are correctly installed.
8 After installation pull on any quick connect fittings to check that each is correctly installed.
9 Start and run the engine to check for correct operation.
3.11 Exhaust Manifold Assembly
Remove

Allow the engine to cool before commencing.

Disconnection of the battery affects certain
vehicle electronic systems, refer to 1.1
WARNING, CAUTION and NOTES before
disconnecting the battery.
1 Disconnect the battery negative terminal.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–78

2 Position a new exhaust manifold gasket onto the exhaust manifold.
3 Apply a 5 mm bead of Loctite 272 thread sealant (or equivalent) to the threads of the exhaust manifold attaching bolts.
4 Install the bolts into the exhaust manifold. This will prevent the gasket from falling off the manifold.
5 Manoeuvre the exhaust manifold into position and install the exhaust manifold attaching bolts.
6 From underneath the vehicle install the exhaust manifold to exhaust pipe flange nuts.
7 Tighten the exhaust manifold attaching bolts to the correct torque specification.
NOTE
When tightening the exhaust manifold to cylinder
head attaching bolts, begin with the centre bolts,
then alternate from side to side to the outer bolts.
Exhaust manifold to cylinder head
attaching bolt torque specification ...........17.0 – 23.0 Nm
8 Apply an anti seize compound such as Caltex Kopr-Kote (or equivalent) to the cleaned heat shield bolt threads. Install the heat shield attaching bolts and tighten to the correct torque specification.
Exhaust manifold heat shield attaching
bolt torque specification ............................8.0 – 12.0 Nm
9 For the right-hand side, install the battery harness ground cable attaching nut through the ground terminal and lower coolant tube mounting lug, and tighten to the correct torque specification.
Battery harness ground terminal
attaching nut torque specification.......................13.0 Nm

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–185

Remove
1 Remove the skid plate.
2 Drain the radiator coolant, refer to 6B1 Engine Cooling – V6.
3 Disconnect the battery negative and positive terminal, refer to 8A Electrical Body & Chassis.
4 Remove the battery from the vehicle.
5 Depressurise the fuel system pressure, refer to 6C Fuel System – V6.
6 Make alignment marks on the bonnet and hinges in order to return the bonnet to the exact original position.
7 Remove the bonnet, refer to 2B Sheet Metal.
8 Remove the rubber hose (2) and air duct (1).

Figure 6A1 – 317

9 Disconnect the barometric sensor connector (1).
Figure 6A1 – 318

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ISUZU KB P190 2007