Engine Mechanical – V6 Page 6A1–42
Page 6A1–42
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.
Material in cylinder bore, caused by:
• broken valve,
• broken piston or ring, or
• dirt or foreign matter entry during engine assembly
procedure. 1 Clean and inspect the cylinder for damaged
components and or foreign matter, refer to 4.7
Cylinder Block.
2 Repair or replace components as required.
Seized crankshaft or connecting rod bearings. Inspect and repair or replace crankshaft, connecting rod
and bearings as required, refer to 4.5 Pistons, Pins, Rings,
Connecting Rods and Big-end Bearings and 4.6
Crankshaft and Main Bearings.
Bent or broken connecting rod. Inspect and repair or replace connecting rod and bearings
as required, refer to 4.5 Pistons, Pins, Rings, Connecting
Rods and Big-end Bearings.
Bent or broken crankshaft. Inspect and repair or replace crankshaft and bearings as
required, refer to 4.6 Crankshaft and Main Bearings.
Seized or broken camshaft. 1 Inspect and replace camshafts as required, refer to
3.19 Camshaft.
2 Inspect camshaft journals and cam caps on cylinder head and repair or replace components as required,
refer to 3.22 Cylinder Head Assembly.
Seized or broken camshaft timing components. 1 Inspect the crankshaft, idler, intake camshaft and
exhaust camshaft sprockets.
2 Inspect the timing chains.
3 Inspect the guides.
4 Inspect the tensioners.
5 Repair or replace components as required, refer to 3.16 Timing Chains, Tensioners, Shoes and Guides.
Seized or broken valve train components. 1 Inspect the stationary hydraulic lash adjusters, refer
to 3.21 Stationary Hydraulic Lash Adjuster.
2 Inspect the rocker arms, re fer to 3.20 Rocker Arm.
3 Inspect the Valves Refer to 3.22 Cylinder Head Assembly.
4 Inspect the valve springs, refer to 3.22 Cylinder Head Assembly.
5 Repair or replace components as required.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–43
Page 6A1–43
2.13 Coolant in Combustion Chamber
Definition
Excessive white smoke and/or coolant type odour emitted from the exhaust pipe may indicate coolant in the combustion
chamber. Low coolant levels, an inoperativ e engine cooling fan or a faulty thermostat may lead to an over-temperature
condition which may cause internal engine component damage. A slower than normal cranking speed may indicate
coolant entering the combustion chamber.
1 Remove the spark plugs and inspect for spark plugs sa turated by coolant and coolant in the cylinder bore.
2 Inspect by performing a cylinder leakage test, refer to 2.16 Cylinder Leakage Test. During this test, excessive air
bubbles in the coolant may indicate a faulty head ga sket, cracked cylinder head or cracked cylinder block.
3 Inspect by performing a cylinder compression test. Two cylinders side-by-side on the cylinder block, with low
compression, may indicate a fa iled cylinder head gasket, refer to 2.15 Engine Compression Test.
Cause Correction
Cracked intake manifold or faulty gasket. Replace components as required, refer to 3.10 Intake
Manifold Assembly – Complete.
Faulty cylinder head gasket. Replace the cylinder head gasket, refer to 3.22 Cylinder
Head Assembly.
Warped cylinder head. Repair or replace the cylinder heads as required, refer to
3.22 Cylinder Head Assembly.
Cracked cylinder liner or block Repair or replace the cylinder block and components as
required, refer to 4.7 Cylinder Block.
Cylinder head or cylinder block porosity. Repair or replace the cylinder block or cylinder heads as
required, refer to 4.7 Cylinder Block or 3.22 Cylinder Head
Assembly.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–44
Page 6A1–44
2.14 Coolant in Engine Oil
Definition
Foamy or discoloured oil or an engine oil overfill condition may indicate coolant entering the engine crankcase. Low
coolant levels, an inoperative engine cooli ng fan or a faulty thermostat may lead to an over-temperature condition which
may result in engine component damage. Contaminat ed engine oil and oil filters must be replaced.
1 Inspect the oil for excessive foaming or an overfill condition. Oil diluted by coolant may not correctly lubricate the
crankshaft bearings, resulting in component damage, refer to 2.10 Lower Engine Noise, Regardless of Engine
Speed .
2 Perform a cylinder leakage test, refer to 2.16 Cylinder Leakage Test. During this procedure, excessive air bubbles
in the engine coolant may indicate a faulty gasket or damaged component.
3 Perform a cylinder compression test. Two cylinders side-by -side on the cylinder block, with low compression, may
indicate a failed cylinder head gasket, refer to 2.15 Engine Compression Test.
Cause Correction
Faulty cylinder head gasket. Replace the cylinder head gasket, refer to 3.22 Cylinder
Head Assembly.
Warped cylinder head. Repair or replace the cylinder heads as required, refer to
3.22 Cylinder Head Assembly.
Cracked cylinder liner or block Repair or replace the cylinder block and components as
required, refer to 4.7 Cylinder Block.
Cylinder head, cylinder block or intake manifold porosity. Repair or replace the cylinder block, cylinder heads or
intake manifold components as required, refer to
4.7 Cylinder Block, 3.22 Cylinder Head Assembly or
3.10 Intake Manifold Assembly – Complete.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–45
Page 6A1–45
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 Section 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 removi ng the fuel pump relay, refer to Section 8A Electrical Body & Chassis .
4 Start the engine to use any resi dual fuel from the fuel lines.
4 Disable the ignition coils by removing fuses 34 and 35, refer to Section 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 While observing the compression tester reading, turn t he 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 per cent 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 exhaus t 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 pos itioned adjacent to each other.
• The engine oil may be contaminated with engine coolant.
• The engine coolant may be cont aminated with engine oil.
Once the fault has been identified, refe r to the relevant service procedure and reinstall the removed components.
Using Tech 2, clear DTCs.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–53
Page 6A1–53
Drive Belt Chirp
Definition
Accessory drive belt chirping can be defined as a high-pitched noise that is heard once per revolution of the drive belt or
a pulley.
NOTE
Chirping during start-up in cold damp conditions
that abates once the engine reaches operating
temperature is considered normal.
Diagnostic Aids
The symptom may be intermittent due to moisture on the driv e belts or pulleys. It may be necessary to spray a small
amount of water on the drive belt to dup licate and confirm a customers concern. If spraying water onto the drive belt
system duplicates the symptom, cleaning the belt pulleys may be the solution.
A loose or incorrectly installed body component, suspension component or other item may be the cause of the noise.
Test Description
The numbers below refer to steps in the diagnostic table.
2 The noise may not be engine related. This step is to confirm the engine is making t he noise. If the engine is not
making the noise, do not proceed further with this diagnostic procedure.
3 The noise may be an internal engine noise. Removing the drive belt and operating the engine briefly will confirm
whether or not the noise is related to the drive belt.
CAUTION
When running the engine with the accessory
drive belt removed, the coolant pump will not
be operating and the engine may overheat if
left unsupervised even for a short period.
NOTE
There may also be a number of DTCs set when
running the engine with the accessory drive belt
removed.
4 Inspect all drive pump pulleys for pilling. NOTE
Pilling is the small balls (p ills) or strings of rubber
in the belt grooves caused by the accumulation of
rubber dust.
6 Misalignment of the accessory drive system pulleys ma y be caused by incorrect mounting of an accessory drive
component (A/C compressor, generator etc.) or pulley. Misa lignment may also be caused by incorrect installation of
a pulley during a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across
two or three pulleys. If a misaligned pulley is found, refer to the relevant component service information for the
correct installation and removal procedures.
10 Inspecting the fasteners can elim inate the possibility that an incorrect fastener has been installed.
12 Inspecting the pulleys for being bent should include inspec ting for a dent or other damage that would prevent the
drive belt from not seating correctly in all of the pulley grooves or on the smooth surface when the back end of the
belt is used as the driving surface.
14 Replacing the drive belt when it is not damaged and there is no excessive p illing will only be a temporary repair.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–55
Page 6A1–55
Drive Belt Squeal
Definition
Accessory drive belt squealing can be defined as a loud screeching noise caused by a slipping drive belt. Belt squeal is
unusual in multi-rib belts. Drive belt squeal generally occurs when a heavy load is applied to the drive belt, such as an
air-conditioning compressor engagement, snapping the throttle, se ized pulley or a faulty accessory drive component.
Diagnostic Aids
If the noise is intermittent, confirm the accessory drive components by varying t heir loads, making sure they are operated
to their maximum capacity. An overcharged A/C system, restrictions in the power steering pressure circuit or a faulty
generator or coolant pump are likely c auses of accessory drive belt squeal.
A loose or incorrectly installed body component, suspension component or other item may be the cause of the noise.
Test Description
The numbers below refer to steps in the diagnostic table.
2 The noise may not be engine related. This step is to confirm the engine is making t he noise. If the engine is not
making the noise, do not proceed further with this diagnostic procedure.
3 The noise may be an internal engine noise. Removing the drive belt and operating the engine briefly will confirm
whether or not the noise is related to the drive belt.
CAUTION
When running the engine with the accessory
drive belt removed, the coolant pump will not
be operating and the engine may overheat if
left unsupervised even for a short period.
NOTE
There may also be a number of DTCs set when
running the engine with the accessory drive belt
removed.
4 Confirms an accessory drive component does not have a se ized bearing. With the belt removed, test the bearings
in the accessory drive co mponents spin free and smooth.
5 Confirms the drive belt tensioner is operating correctly. If the drive belt tensioner is not operating correctly, drive
belt tension will not be maintained, resulting in a belt squealing noise
6 Confirms the belt is not too long, which would prevent the tensioner from working as intended. Also, if an
excessively long belt has been fitted, it may also be r outed incorrectly and may be turning an accessory drive
component in the wrong direction.
7 Misalignment of the pulleys may be caused by one of the following:
• Incorrect mounting of an accessory drive component,
• Incorrect installation of an accessory drive pulley or,
• Bent or damaged pulley.
Test for a misaligned pulley using a straight edge in the pulley grooves across 2 or 3 pulleys. If a misaligned pulley is found, refer to the relevant component service info rmation for the correct installation and removal procedures.
8 This test is to confirm the pulleys are the correct di ameter and/or width. Using a known good vehicle, compare the
pulley sizes.
Diagnostic Table
Step Action Yes No
1
Did you review the information provided in 2.2 Symptoms, and
perform the required inspections. Go to Step 2 Go to
2.2 Symptoms
2 Confirm the customer compla int. Is there a squealing noise?
Go to Step 3 Refer to Diagnostic
Aids in this Section
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–57
Page 6A1–57
Drive Belt Whine
Definition
Accessory drive belt whine can be defined as a high-pitched continuous noise that is most likely to be caused by a failed
bearing in one of the acce ssory drive components.
Diagnostic Aids
The drive belts themselves will not caus e a whine. If the noise is intermittent, confirm the accessory drive components by
varying their loads, making sure they are operated to their maximum capacity. An overcharged A/C system, restrictions
in the power steering pressure circuit or a faulty generator or coolant pump ar e likely causes of accessory drive belt
whine.
Test Description
The numbers below refer to steps in the diagnostic table.
3 The noise may be an internal engine noise. Removing the drive belt and operating the engine briefly will confirm
whether or not the noise is related to the drive belt.
CAUTION
When running the engine with the accessory
drive belt removed, the coolant pump will not
be operating and the engine may overheat if
left unsupervised even for a short period.
NOTE
There may also be a number of DTCs set when
running the engine with the accessory drive belt
removed.
4 The inspection of bearings should include the following accessory drive components:
• drive belt tensioners,
• drive belt idlers,
• generator,
• power steering pump,
• coolant pump, and
• A/C compressor.
The drive belt may need to be installed and the accessory drive components operated separ ately, at varying loads
to confirm the location of the faulty bearing, refer to the relevant Sections for component inspection and repair
procedures.
Diagnostic Table
Step Action Yes No
1
Did you review the information provided in 2.2 Symptoms, and
perform the required inspections. Go to Step 2 Go to
2.2 Symptoms
2 Confirm the customer compla int. Is there a whining noise?
Go to Step 3 Refer to Diagnostic
Aids in this Section
3 1 Remove the drive belt, refer to 3.5 Accessory Drive Belt.
2 Operate the engine for no more than 40 seconds.
Does the whining noise still exist? Accessory drive
system OK
Go to 2.2
Symptoms, and
restart the diagnosis Go to Step 4
4 Inspect the accessory drive components for a faulty or seized
bearings and general malfunctions.
Did you find and correct any faulty/seized bearings or general
malfunctions in the accessory drive system? Go to Step 5 Refer to Diagnostic
Aids in this Section
5 Reinstall the accessory drive belt and operate the system to confirm
the repair.
Did you correct the whine? Accessory drive
system OK Go to 2.2
Symptoms, and
restart the diagnosis
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–58
Page 6A1–58
Drive Belt Rumble
Definition
Accessory drive belt rumble can be defined as a low pitch tapping, knocking or thumping noise heard at or just above
idle, once per rotation of the drive belt or a specific co mponent. Drive belt rumble is generally caused by one of the
following:
• pilling or strings in the drive belt grooves,
• separation of the drive belt, or
• a damaged or faulty drive belt.
NOTE
Pilling is the small balls (p ills) or strings of rubber
in the belt grooves caused by the accumulation of
rubber dust.
Diagnostic Aids
Vibration from the engine may cause a body component or other parts to emit a rumbling noise.
The drive belt may have a condition that cannot be seen or felt. Sometimes the replacement of the belt may be the only
way to confirm the belt is faulty.
If the drive belt has been replaced and the di agnostic table completed, but the rumble is still present only when the drive
belt is installed, an accessory drive component such as t he A/C compressor may be the cause. Varying the load to each
accessory drive component in turn, should help isolate which component is causing the noise.
Test Description
The numbers below refer to steps in the diagnostic table.
2 Confirms the symptom exists at the time of di agnosis. Other vehicle components may be causing the noise.
3 Confirms the accessory drive belt is the cause of the noise. Drive belt rumbling is often confused with an internal
engine noise due to the similarity in the description. Removing the drive belt and operating the engine briefly will
confirm whether or not the noise is related to the drive belt.
CAUTION
When running the engine with the accessory
drive belt removed, the coolant pump will not
be operating and the engine may overheat if
left unsupervised even for a short period.
NOTE
There may also be a number of DTCs set when
running the engine with the accessory drive belt
removed.
4 Inspecting the drive belt is to ensure t hat it is not causing the noise. Small cracks across the ribs of the drive belt
will not cause the noise and are not just ification alone to replace the belt. Belt separation can be identified by the
ply of the belt separating and may be seen at the edge of the belt or felt as lumps under the belt.
5 Small amounts of pilling is a normal condition and is deemed acceptable. When the pilling is severe (33% of the
belt groove depth), the belt does not have a smoot h surface to run on and should be replaced.
Diagnostic Table
Step Action Yes No
1
Did you review the information provided in 2.2 Symptoms, and
perform the required inspections. Go to Step 2 Go to
2.2 Symptoms
2 Confirm the customer compla int. Is there a rumbling noise?
Go to Step 3 Refer to Diagnostic
Aids in this Section
3 1 Remove the drive belt, refer to 3.5 Accessory Drive Belt.
2 Operate the engine for no more than 40 seconds.
Does the rumbling noise still exist? Accessory drive
system OK
Go to 2.2
Symptoms, and
restart the diagnosis Go to Step 4
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007