Engine Mechanical – V6 Page 6A1–21
1.4 Engine Construction
Cylinder Block
The cylinder block (1) is constructed from aluminium alloy
with cast-in-place iron cylinder bore liners.
Each of the four copper-infiltrated sintered steel main
bearing caps are attached to the cylinder block by six bolts.
Along with two outer and two inner bolts, two side bolts are
used in the deep skirt block for increased block stiffness.
The crankshaft thrust bearing is mounted in the third main
bearing cap.
To prevent aeration, oil return from the valve train and
cylinder heads is channelled away from the reciprocating
components through oil drain back passages incorporated
into the cylinder heads and engine block. Pressure
actuated piston oil cooling jets are mounted between
opposing cylinders.
Figure 6A1 – 14
Cylinder Heads
The cylinder heads (1) are semi-permanent mould cast
aluminium with powdered metal valve seat inserts and
valve guides.
Figure 6A1 – 15
Each cylinder head contains four valves per cylinder. The
valves (1) are actuated by the rocker arms (2) that pivot on
stationary hydraulic lash adjusters (3), which are oil-fed to
maintain valve / rocker lash.
The separate exhaust and intake camshafts are supported
by four bearings machined into the cylinder head. The front
camshaft bearing cap is used as a thrust control surface for
each camshaft.
A tube (4) is pressed into each cylinder head in three
places that shields each spark plug. An ignition coil
assembly is mounted directly on each spark plug, through
each spark plug tube.
Figure 6A1 – 16
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–32
secondary ignition circuit is grounded out during
diagnosis.
A light rattle/tapping noise may indicate a valve train/upper engine concern, while a low rumble/knocking may indicate a
crankshaft, piston or lower engine concern.
Cause Correction
Oil filter anti-drain back valve faulty. Replace the oil filter adaptor, refer to 3.3 Oil Filter
Adaptor.
Incorrect oil viscosity. Drain the engine oil and replace with the correct viscosity
oil, refer to 3.1 Engine Oil.
High camshaft stationary hydraulic lash adjuster (SHLA)
leak down rate. Replace the SHLA as required, refer to 3.21 Stationary
Hydraulic Lash Adjuster.
W orn crankshaft thrust bearing. Inspect and replace the crankshaft and/or bearings as
required, refer to 4.6 Crankshaft and Main Bearings.
Damaged or faulty oil filter by-pass valve. 1 Inspect the oil filter by-pass valve for correct
operation.
2 Repair or replace the oil filter adaptor/by-pass valve as required.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–33
2.9 Upper Engine Noise, Regardless of
Engine Speed
NOTE
A cold piston knock, which disappears in
approximately 1.5 minutes from start up, should
be considered acceptable. A cold engine knock
usually disappears when the specific cylinder’s
secondary ignition circuit is grounded out during
diagnosis.
A light rattle/tapping noise may indicate a valve train/upper engine concern, while a low rumble/knocking may indicate a
crankshaft, piston or lower engine concern.
Cause Correction
Low oil pressure. 1 Perform an oil pressure test, refer to 2.19
Engine Oil Pressure Diagnosis.
2 Repair or replace the engine oil pump as required, refer to 3.17 Oil Pump Assembly.
W orn or loose stationary hydraulic lash adjusters (SHLA)
and/or valve rocker arms.
The SHLAs, rocker arm and roller bearings should be intact
and in the correct position. 1 Clean, inspect and replace the camshaft lash
adjusters as required, refer to 3.21 Stationary
Hydraulic Lash Adjuster.
2 Replace the SHLAs and/or rocker arms as required, refer to 3.21 Stationary Hydraulic Lash Adjuster or
3.20 Rocker Arm.
Incorrect lubrication to the stationary hydraulic lash
adjusters and valve rocker arm. Inspect the following components and repair or replace as
required:
• valve rocker arms, refer to 3.20 Rocker Arm.
• stationary hydraulic lash adjusters, refer to 3.21
Stationary Hydraulic Lash Adjuster.
• oil filter by-pass valve, refer to 3.3 Oil Filter
Adaptor.
• oil pump and suction pipe, refer to 3.17 Oil Pump
Assembly.
• cylinder head oil galleries, refer to 3.22 Cylinder Head
Assembly.
• cylinder block oil galleries, refer to 4.7 Cylinder
Block.
Broken Valve Spring. Replace the valve spring, refer to 3.22 Cylinder Head
Assembly.
Stretched or broken timing chain/s and/or damaged timing
chain sprocket teeth. Replace the timing chains or sprockets as required, refer to
3.16 Timing Chains, Tensioners, Shoes and Guides.
W orn or faulty timing chain tensioner or guide. Replace the timing chains or sprockets as required, refer to
3.16 Timing Chains, Tensioners, Shoes and Guides.
W orn camshaft lobes. Replace the camshaft/s and SHLAs as required, refer to
3.19 Camshaft or 3.21 Stationary Hydraulic Lash
Adjuster.
W orn valve guides and/or valve stems. Inspect and repair or replace valves and valve guides as
required, refer to 3.22 Cylinder Head Assembly.
Stuck valves.
Carbon on the valve stem or valve seat may cause the
valve to stay open. Inspect and repair or replace valves and valve guides as
required, refer to 3.22 Cylinder Head Assembly.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–34
2.10 Lower Engine Noise, Regardless of
Engine Speed
NOTE
A cold piston knock which disappears in
approximately 1.5 minutes from start up should
be considered acceptable. A cold engine knock
usually disappears when the specific cylinder’s
secondary ignition circuit is grounded out during
diagnosis.
A light rattle/tapping noise may indicate a valve train/upper engine concern, while a low rumble/knocking may indicate a
crankshaft, piston or lower engine concern.
Cause Correction
Low oil pressure. 1 Perform an oil pressure test, refer to 2.19
Engine Oil Pressure Diagnosis.
2 Repair or replace the engine oil pump as required, refer to 3.17 Oil Pump Assembly.
W orn accessory drive components.
Abnormalities such as severe cracking, bumps, stretching
or missing areas on an accessory drive belt and/or
misalignment of accessory drive system components. Inspect the accessory drive system, repair or replace
components as required, refer to 3.5 Accessory
Drive Belt.
Loose or damaged crankshaft balancer and pulley
assembly. Repair or replace the crankshaft balancer and pulley
assembly as required, refer to 3.13 Crankshaft Balancer
Assembly.
Detonation or spark knock. Confirm the correct operation of the ignition system, refer to
6C1-2 Engine Management – V6 – Diagnostics.
Loose torque converter bolts. Inspect and tighten the torque converter bolts to the correct
torque specification, refer to 7C4 Automatic Transmission –
4L60E – On-vehicle Servicing.
Loose or damaged flexplate. Repair or replace the flexplate as required, refer to 4.3
Flexplate Assembly.
Oil pump suction pipe loose, damaged or restricted. Clean, inspect and repair/replace the oil pump suction pipe as required, refer to 4.2 Oil Pan and Oil Pump Suction
Pipe Assembly.
Excessive piston-to-cylinder bore clearance. Inspect the piston and cylinder bore and repair/replace
components as required, refer to 4.5 Pistons, Pins,
Rings, Connecting Rods and Big-end Bearings and 4.7
Cylinder Block.
Excessive connecting rod bearing clearance. Inspect the connecting rod, crankshaft and bearings and
repair/replace components as required, refer to 4.5
Pistons, Pins, Rings, Connecting Rods and Big-
end Bearings and 4.6 Crankshaft and Main Bearings.
Excessive piston pin to bore clearance. Inspect the pistons and pins and repair/replace components
as required, refer to 4.5 Pistons, Pins, Rings,
Connecting Rods and Big-end Bearings.
Excessive crankshaft main bearing clearance. Inspect the crankshaft, cylinder block journals, main
bearings and main bearing caps and repair/replace
components as required, refer to 4.6 Crankshaft
and Main Bearings and 4.7Cylinder Block.
Incorrect piston, pin and connecting rod installation.
Pistons must be installed with the mark or dimple facing the
front of the engine. Piston pins must be centred in the
piston pin bore. Confirm the pistons, pins and connecting rods are installed
correctly and repair if required, refer to 4.5 Pistons, Pins,
Rings, Connecting Rods and Big-end Bearings.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–35
2.11 Engine Noise Under Load
NOTE
A cold piston knock which disappears in
approximately 1.5 minutes from start up, should
be considered acceptable. A cold engine knock
usually disappears when the specific cylinder’s
secondary ignition circuit is grounded out during
diagnosis.
A light rattle/tapping noise may indicate a valve train/upper engine concern, while a low rumble/knocking may indicate a
crankshaft, piston or lower engine concern.
Cause Correction
Low oil pressure. 1 Perform an oil pressure test, refer to 2.19
Engine Oil Pressure Diagnosis.
2 Repair or replace the engine oil pump as required, refer to 3.17 Oil Pump Assembly.
Detonation or spark knock. Confirm the correct operation of the ignition system, refer to
6C1-2 Engine Management – V6 – Diagnostics.
Loose torque converter bolts. Inspect and tighten the torque converter bolts to the correct
torque specification, refer to 7C1 Automatic – 4L60E –
General Information – 4L60E – General Information.
Cracked flexplate. Replace the flywheel/flex-plate as required, refer to 4.3
Flexplate Assembly.
Excessive connecting rod bearing clearance. Inspect the connecting rod, crankshaft and bearings and
repair/replace components as required, refer to 4.5
Pistons, Pins, Rings, Connecting Rods and Big-
end Bearings and 4.6 Crankshaft and Main Bearings.
Excessive crankshaft bearing clearance Inspect the crankshaft, cylinder block journals, main
bearings and main bearing caps and repair/replace
components as required, refer to 4.6 Crankshaft
and Main Bearings and 4.7Cylinder Block.
2.12 Engine Will Not Crank – Crankshaft Will Not Rotate
Cause Correction
Seized accessory drive system component. 1 Remove the accessory drive belt, refer to 3.5
Accessory Drive Belt.
2 Rotate the crankshaft by hand at the balancer pulley or flywheel.
3 Repair or replace accessory drive system components as required.
Hydraulically locked cylinder caused by:
• coolant in cylinder,
• oil in cylinder, or
• fuel in cylinder. 1 Remove the spark plugs and check for fluid, refer to
6C1-3 Engine Management – V6 – Service
Operations.
2 Inspect for broken head gasket/s.
3 Inspect for cracked engine block or cylinder head.
4 Inspect for sticking fuel injector.
5 Repair or replace components as required.
Seized torque converter. 1 Remove the torque converter bolts, refer to 7C1
Automatic – 4L60E – General Information – 4L60E –
General Information.
2 Rotate the crankshaft by hand at the balancer pulley or flywheel.
3 Repair or replace torque converter as required.
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ISUZU KB P190 2007
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 6A1–80
6 Remove the bolt (1) attaching the ground connector
(2) to the cylinder head.
7 Fro the left-hand side, disconnect the engine coolant temperature (ECT) sensor wiring connector (3).
8 Unclip the engine wiring harness retaining lugs from the side of the camshaft cover.
Figure 6A1 – 63
9 For the right-hand side, remove the engine wiring harness retaining clip (1) from the engine control
module (ECM) bracket (2).
Figure 6A1 – 64
10 Disconnect the camshaft position (CMP) sensor wiring connector (1).
11 Unclip the engine wiring harness retaining lug (3) from the front of the camshaft cover.
12 Remove the ignition coil assemblies; refer to 6C1-3 Engine Management – V6 – Service Operations.
13 Move the engine wiring harness clear of the camshaft cover.
Figure 6A1 – 65
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–198
k Timing chains, tensioners, shoes, guides & sprockets, refer to 3.16 Timing Chains, Tensioners, Shoes and
Guides.
l Cylinder head assemblies, refer to 3.22 Cylinder Head Assembly.
m Oil pan assembly, refer to 4.2 Oil Pan and Oil Pump Suction Pipe Assembly.
n Piston and connecting rod assemblies, refer to 4.5 Pistons, Pins, Rings, Connecting Rods and Big-end Bearings.
o Crankshaft assembly, refer to 4.6 Crankshaft and Main Bearings.
p Piston oil nozzles, refer 4.5 Pistons, Pins, Rings, Connecting Rods and Big-end Bearings.
Reassemble
Reassembly of the engine assembly is the reverse of the disassembly procedure.
Reinstall
Reinstallation of the engine assembly is the reverse to the removal procedure, noting the following:
NOTE
Refer to 6 Torque Wrench Specifications
for the correct torque specifications.
1 Tighten the fasteners to the correct torque specification.
Engine ground connector bolt
torque specification ............................................10.0 Nm
Power steering high pressure line
attaching bolt torque specification .............8.0 – 12.0 Nm
Power steering high pressure line
flare nut torque specification ...................25.0 – 35.0 Nm
Engine mount to frame attaching bolt
torque specification .................................44.0 – 60.0 Nm
Knock Sensor Attaching Nut
torque specification ............................................23.0 Nm
2 Use only the specified engine lubricant type and quantity. It is recommended that a fluorescent oil dye, such as that contained in J 28481-B, be added to assist in any future oil leak diagnosis.
3 Fill the cooling system with the correct quantity and grade of coolant, refer to 6B1 Engine Cooling – V6.
4 Check transmission fluid level, replenishing as required, using the specified lubricant for the transmission fitted, refer to 7C1 Automatic – 4L60E – General Information.
5 Disable the ignition system, refer to 6C1-3 Engine Management – V6 – Service Operations.
6 Crank the engine several times. Listen for any unusual noises or evidence that parts are binding.
7 Enable the ignition system. Start the engine and listen for any unusual noises.
8 Check the vehicle oil pressure gauge or warning indicator and confirm the engine has acceptable oil pressure. If required, install an oil pressure gauge and measure the engine oil pressure, refer to 2.19 Engine Oil Pressure
Diagnosis.
9 Run the engine at about 1,000 r.p.m. until the engine has reached normal operating temperature.
10 Listen for any unusual noises.
11 Check for oil, fuel, coolant and exhaust leaks while the engine is running, correcting as required.
12 Perform a final inspection for correct engine oil and coolant levels.
4.2 Oil Pan and Oil Pump Suction Pipe Assembly
Remove
1 Remove the engine assembly from the vehicle, refer to 4.1 Engine .
2 Separate the engine and transmission assemblies, refer to 7C1 Automatic – 4L60E – General Information.
3 Mount the engine assembly on a suitable engine stand.
4 Remove the engine front cover, refer to 3.15 Front Cover Assembly.
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