Engine Mechanical – V6 Page 6A1–22
Page 6A1–22
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-inf iltrated 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 fo r increased block stiffness.
The crankshaft thrust bearing is mounted in the third main
bearing cap.
To prevent aeration, oil retu rn 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 adjuste rs (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
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–25
Page 6A1–25
1.5 Engine Lubrication System
Lubrication Description
A structural diecast aluminium oil pan is fitted that incorporates an oil suction pipe, an oil deflector and an oil level
sensor. The oil suction pipe is bolted in to the oil pan and seals to the bottom of the cylinder block with a gasket. The oil
deflector is bolted to the upper portion of the oil pan and ensures oil supply is maintained under all conditions. The oil
level sensor is mounted thr ough the bottom of the oil pan.
A crankshaft driven gerotor oil pump is mounted to the front of the cylinder block. The pump, which incorporates an
internal pressure-relief valve, draws oil from the oil sucti on tube through the lower passage in the cylinder block. Oil is
then directed through an upper passage to the left-hand side of the cylinder block where the oil filter adapter is mounted.
The oil filter adapter incorporat es a top-access, cartridge style oil filter. The filter is accessed through a screw-on cap tha t
incorporates an oil bypass valve. The o il filter adapter housing incorporates a drain back control valve and a threaded oil
pressure sender. Oil flows through a lower passage within the oil filter adapter and through the o il filter cartridge. Filtered
oil travels back through the upper passage of the adapter and into the engine block.
Oil is then directed up and across the front of the cylinder block, through several drilled passages. These front passages
feed oil to each cylinder head, the passage for the main bearings and piston oil jets, the right-hand and left-hand
secondary idler sprockets and to t he primary timing chain tensioner.
Each cylinder head passage directs oil into oiling circuits for the stationary hydraulic la sh adjusters (SHLAs) and the
camshaft bearing journals. An additional passage in the cy linder head also directs oil to the secondary timing chain
tensioner.
The oil passage that supplies oil to the main bearings also s upplies oil to pressure actuated piston cooling oil jets. Each
oil jet is mounted between opposing cylinder bores and directs oil to the two bores to provide extra cooling and control
piston temperatures.
From the front passages, oil is directed to the front of the block where t he right-hand and left-hand intermediate drive
shaft sprockets and the primary timing chain tensioner are mounted. Each camshaft timing chain tensioner relies on a
gasket to maintain an oil rese rve after the engine is turned off. All camshaft timing chain tensioners incorporate a small
oil jet to supply an oil spray onto the camshaft timing chain components.
Oil returns to the oil pan, either through the camshaft timing chain area or through the drain back passages on the
outboard walls of the cylinder heads and cylinder block.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–27
Page 6A1–27
Use of Room Temperature Vulcanising and Anaerobic Sealer
CAUTION
A number of sealant types are commonly
used in engines. Examples are; room
temperature vulcanising (RTV) sealer,
anaerobic gasket eliminator sealer, and
anaerobic thread sealant and pipe joint
compound. The correct type of sealant and
amount must be used in the specified location
to prevent oil leaks. Do not interchange the
different types of sealers.
Room Temperature Vulcanising Sealer
• Room temperature vulcanising (RTV) s ealant hardens when exposed to air. This type of sealer is used where two
non-rigid parts (such as the intake manifold and the engine block) are assembled together.
• Do not use RTV sealant in areas where extreme temper atures are experienced. These areas include the exhaust
manifold, head gasket, or other surfaces w here a gasket eliminator is specified.
• Follow all safety recommendations and di rections that are on the container.
• To remove the sealant or the gasket mate rial, refer to Replacing Engine Gaskets.
• Apply RTV to a clean surface. Use a bead size as specified in the service procedure. Run the bead to the inside of
any bolt holes. Do not allow the sealer to enter any bli nd threaded holes, as it may prevent the bolt from clamping
correctly or cause damage when the bolt is tightened.
• Assemble components while RTV is still wet (within 3 minutes). Do not wait for RTV to skin over.
• Tighten the bolts to the correct torque specification. Do not over-tighten.
Anaerobic Sealer
• Anaerobic gasket eliminator or thread sealant, hardens in t he absence of air. This type sealer is used where two
rigid parts (such as castings) are assembled together, w here fasteners are subjected to vibration, or where the
holes are not blind. When two rigid parts are disassembled and no sealer or gasket is readily noticeable, the parts
were probably assembled using a gasket eliminator.
• Follow all safety recommendations and di rections that are on the container.
• To remove the sealant or the gasket mate rial, refer to Replacing Engine Gaskets.
• Apply a continuous bead of gasket eliminator to one flange or on the bolt/stud thread. All surfaces must be clean
and dry.
• Spread the sealer evenly to achieve a uniform coating on the sealing surface.
• Do not allow the sealer to enter any blind threaded holes as it may prevent the bolt from clamping correctly or
cause damage when tightened.
CAUTION
Anaerobic sealed joints that are partially
tightened and allowed to cure more than five
minutes may result in incorrect shimming and
sealing of the joint.
• Tighten the bolts to the correct torque specification. Do not over-tighten.
• After correctly tightening the fasteners, remove t he excess sealer from the outside of the joint.
BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–48
Page 6A1–48
2.18 Engine Oil Leak Diagnosis
Introduction
It is important to correctly identify the source of an engine oil leak. For example, a power steering fluid leak or spillage
during servicing can travel across the va lley area of the engine and run-out the weep hole, which is located at the back of
the cylinder block. Failure to correctly identify the source of an engine oil leak can lead to unnecessary replacement of
engine components.
Most fluid leaks can be repaired by repairi ng or replacing the faulty component or resealing the gasket surface. However,
once a leak is identified it is im portant to determine and repair the c ause as well as the leak itself.
Locating and Identifying the Leak
Inspect the leaking fluid and determine whet her it is engine oil, transmission fluid, power steering fluid, brake fluid or
some other fluid. If unsure of the source of the leaking lubricant, a quick check of fluid levels should indicate where the
fluid is coming from, as one or more fluid level should be low.
Visual Inspection
Once the type of leaking fluid has been determined, a visual inspection of the affected system should be performed.
When performing the visual inspection:
1 Bring the vehicle to the normal operating temperature.
2 Park the vehicle over a large s heet of paper or other clean surface.
3 Leave the vehicle idling for 2-3 minut es, then check for dripping fluid.
4 If required, identify the type of fluid leak ing and the approximate location of the leak.
5 Visually inspect the suspected area. A small mirror may assist viewing areas that are difficult to see normally.
6 Check for leaks at all sealing surfaces and fittings.
7 Check for any cracked or damaged components.
8 If the leak cannot be located, completely clean the entire engine and surrounding components, drive the vehicle at
normal operating temperature for several k ilometres and then repeat Steps 3 to 8.
9 If the leak still cannot be located, proceed with either the Powder Method or Black Light and Dye Method as
outlined below.
Powder Method
1 Completely clean the entir e engine and surrounding components.
2 Apply an aerosol type powder (e.g. f oot powder) to the suspected area.
3 Operate the vehicle at normal operating temperature and at varying speeds for several kilometres.
4 Identify the source of the leak from the discoloration of the powder around the suspect components.
5 If required, use a small mirror to assist in vi ewing areas that are difficult to see normally.
6 Refer to Possible Causes for Engine Oil Leaks in this Section, and repair or replace components as required.
Black Light and Dye Method
A black light and die kit Tool No. J28428-E or a commercially av ailable equivalent is available to technicians to aid in
engine oil leak diagnosis. When using a black light and die kit fo r the first time, it is recommended the technician read the
manufacturers instructions prior to using the kit.
1 Add the specified amount of dye, as per manufacturers instructions, into the engine or suspected source of the oil
leak.
2 Operate the vehicle at normal operating temperature and at varying speeds for several kilometres.
3 With the vehicle parked on a flat leve l surface, aim the black light at the suspected component/s. The dyed fluid will
appear as a yellow path leading to the oil leak source
4 Refer to Possible Causes for Engine Oil Leaks in this Section, and repair or replace components as required.
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 6A1–54
Page 6A1–54
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 chirping 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 chirping noise still exist? Accessory drive
system OK.
Go to 2.2
Symptoms, and
restart the diagnosis
of the noise Go to Step 4
4
Inspect for severe pilling, i.e. in excess of 33% of the belt groove
depth.
Do the belt grooves have pilling? Go to Step 5 Go to Step 6
5 Clean the drive belt pulleys with a wire brush.
Are the belt pulleys clean? Go to Step 15 Go to Step 6
6 Inspect for misalignment of the pulleys.
Are the pulleys misaligned? Go to Step 7 Go to Step 8
7 Replace or repair misaligned pulleys.
Did you complete the repair? Go to Step 15 —
8
Inspect for any bent or damaged accessory drive component
mounting brackets.
Did you find any bent or damaged brackets? Go to Step 9 Go to Step 10
9 Replace or repair any bent or damaged Brackets. Did you complete the repairs? Go to Step 15 —
10 Inspect for missing, loose or incorrect fasteners.
Did you find any missing, loose or incorrect fasteners? Go to Step 11 Go to Step 12
11
Tighten any loose fasteners to the to rque specification as provided in
provided in 6. Torque Wrench Specifications.
Replace any incorrect or missing fasteners.
Did you complete the repairs? Go to Step 15 —
12 Inspect for a bent pulley.
Did you find any bent pulleys? Go to Step 13 Go to Step 14
13 Replace bent pulleys as required.
Did you complete the repair? Go to Step 15 —
14 Replace the accessory drive belt, re
fer to 3.5 Accessory Drive Belt.
Did you complete the repair? Go to Step 15 —
15
Reinstall the accessory drive belt and operate the system to confirm
the repair.
Did you correct the chirp noise? 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 6A1–55
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 6A1–58
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