2007 ISUZU KB P190 check engine light

Engine Mechanical – V6 Page 6A1–171

Valve Seat Width Measurement Procedure
1 Measure the valve seat (1) width in the cylinder head
using a scale (2).

Figure 6A1 – 292
2 Measure the seat width on the valve face (1) using a correct scale.
CAUTION
The seat contact area must be at least
0.5 mm from the outer diameter (margin) of
the valve. If the contact area is too close to
the margins, the seat must be reconditioned
to move the contact area away from the
margin.
3 Compare the measurements with the specifications, refer to 5 Specifications.
4 If the seat widths are acceptable, check the valve seat roundness, refer to Valve Seat Roundness
Measurement Procedure in this Section.
5 If the seat width is not acceptable, grind the valve seat to bring the width back to specification. Correct
valve seat width is critical to providing the correct
amount of valve heat dissipation, refer to Valve and
Seat Reconditioning Procedure in this Section.

Figure 6A1 – 293
Valve Seat Roundness Measurement Procedure
1 Measure the valve seat roundness using a dial indicator attached to a tapered pilot installed in the guide. The pilot should have a slight bind when installed in the guide.
CAUTION
The correct size pilot must be used. Do not
use adjustable diameter pilots. Adjustable
pilots may damage the valve guides.
2 Compare your measurements with the specifications, refer to 5 Specifications.
3 If the valve seat exceeds the roundness specification, grind the valve and valve seat, refer to Valve and Seat Reconditioning Procedure in this Section.
4 If new valves are being used, the valve seat roundness must be within 0.05 mm.

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Engine Mechanical – V6 Page 6A1–172

Valve Margin Measurement Procedure
1 Measure the valve margin using an appropriate scale.
2 Refer to 5 Specifications for minimum valve margin and compare them to your measurements.
3 If the valve margins are beyond specification, replace the valves.
4 If the valve margins are within specification and do not require refacing, test the valve for seat
concentricity, refer to Valve-to-Seat Concentricity
Measurement Procedure in this Section.

Figure 6A1 – 294
Valve-to-Seat Concentricity Measurement Procedure
Checking the valve-to-seat concentricity determines whether the valve and seat are sealing correctly.
Measure the valve face and the valve seat to ensure correct valve sealing.
1 Coat the valve face lightly with blue dye (3).
2 Install the valve in the cylinder head.
3 Turn the valve against the seat with enough pressure to wear off the dye.
4 Remove the valve from the cylinder head.
5 Inspect the valve face.
NOTE
• If the valve face is concentric, providing a
correct seal, with the valve stem, a continuous
mark (1) will be made around the entire face (2).
• The wear mark must be at least 0.5 mm from
the margin of the valve. If the wear mark is too
close to the margin, the seat must be
reconditioned to move the contact area away
from the margin.
• If the face is not concentric with the stem, the
mark will not be continuous around the valve
face. The valve should be refaced or replaced
and the seat must be reconditioned, refer to
Valve and Seat Reconditioning Procedure in
this Section.
Figure 6A1 – 295
Valve and Seat Reconditioning Procedure
If the valve seat width, roundness or concentricity are beyond specifications, grind the seats in order to ensure correct
heat dissipation and prevent the build up of carbon on the seats.
If valve seat reconditioning is required, reface the valve face, unless a new valve is used.

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Engine Mechanical – V6 Page 6A1–2
Page 6A1–2
Visual / Physical Inspection ................................................................................................... .............................31
Intermittent ................................................................................................................... ........................................31
2.3 Engine Misfire without In ternal Engine Noises .................................................................................. ...............32
2.4 Engine Misfire with Abnormal In ternal Lower Engine Noises...................................................................... ....34
2.5 Engine Misfire with Abno rmal Valve Train Noise ................................................................................. .............35
2.6 Engine Misfire with Coolant Consumption ........................................................................................ ................36
2.7 Engine Misfire with E xcessive Oil Consumption .................................................................................. ............37
2.8 Engine Noise on Start-up, but only Lasting a Few Seconds ....................................................................... .....38
2.9 Upper Engine Noise, Rega rdless of Engine Speed................................................................................. ..........39
2.10 Lower Engine Noise, Rega rdless of Engine Speed ................................................................................. .........40
2.11 Engine Noise Under Load ................................................................................................................................... 41
2.12 Engine Will Not Crank – Crankshaft Will Not Rotate ............................................................................. ...........42
2.13 Coolant in Com bustion Chamber .................................................................................................. .....................43
Definition ..................................................................................................................... .........................................43
2.14 Coolant in Engine Oil........................................................................................................................................... 44
Definition ..............................................................................................................................................................44
2.15 Engine Compression Test........................................................................................................ ...........................45
Preliminary Steps................................................................................................................................................. 45
Engine Cylinder Compression Test ............................................................................................... ....................45
Test Result Evaluation ......................................................................................................... ...............................45
2.16 Cylinder Leakage Test .......................................................................................................... ...............................46
2.17 Engine Oil Consumption Diagnosis ............................................................................................... ....................47
Definition ..................................................................................................................... .........................................47
2.18 Engine Oil Leak Diagnosis .................................................................................................................................. 48
Introduction ..........................................................................................................................................................48
Locating and Identifying the Leak .............................................................................................. ........................48
Visual Inspection .............................................................................................................. ...................................48
Powder Method .................................................................................................................. ..................................48
Black Light and Dye Method ............................................................................................................................... 48
Possible Causes for Engine Oil Leaks ........................................................................................... ....................49
2.19 Engine Oil Pressu re Diagnosis .................................................................................................. .........................50
2.20 Accessory Drive Belt Diagnosis ................................................................................................. ........................51
Tension Check .................................................................................................................. ...................................51
Inspect ........................................................................................................................ ..........................................52
Drive Belt Chirp .................................................................................................................................................... 53
Definition ..................................................................................................................... .....................................53
Diagnostic Aids................................................................................................................................................. 53
Test Description ............................................................................................................... ................................53
Diagnostic Table............................................................................................................... ................................54
Drive Belt Squeal .............................................................................................................. ...................................55
Definition ..................................................................................................................... .....................................55
Diagnostic Aids................................................................................................................................................. 55
Test Description ............................................................................................................... ................................55
Diagnostic Table............................................................................................................... ................................55
Drive Belt Whine .................................................................................................................................................. 57
Definition ..................................................................................................................... .....................................57
Diagnostic Aids................................................................................................................................................. 57
Test Description ............................................................................................................... ................................57
Diagnostic Table............................................................................................................... ................................57
Drive Belt Rumble .............................................................................................................. ..................................58
Definition ..................................................................................................................... .....................................58
Diagnostic Aids................................................................................................................................................. 58
Test Description ............................................................................................................... ................................58
Diagnostic Table............................................................................................................... ................................58
Drive Belt Vibration........................................................................................................... ...................................60
Definition ..................................................................................................................... .....................................60
Diagnostic Aids................................................................................................................................................. 60
Test Description ............................................................................................................... ................................60
Diagnostic Table............................................................................................................... ................................60
Drive Belt Falls Off ........................................................................................................... ....................................62

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–33
Page 6A1–33
Cause Correction
Faulty cylinder head gasket and/or cracking or other
damage to the cylinder head and cylinder block coolant
passages.
Coolant consumption may or may not cause the engine to
overheat. 1 Inspect the spark plugs for
coolant saturation, refer to
6C1-3 Engine Management – V6 – Service
Operations.
2 Inspect the cylinder heads, cylinder block and/or head gaskets, refer to 3.22 Cylinder Head Assembly
and/or 4.7 Cylinder Block.
3 Repair or replace components as required.
Worn piston rings.
Oil consumption may or ma y not cause the engine to
misfire. 1 Inspect the spark plugs for oil deposits, refer to 6C1-3
Engine Management – V6 – Service Operations.
2 Check the cylinders for a loss of compression, refer to 2.15 Engine Compression Test.
3 Perform compression testing to identify the cause of
low compression.
4 Repair or replace components as required.
A damaged crankshaft reluctor wheel.
A damaged crankshaft reluctor wheel can result in different
symptoms depending on the severity and location of the
damage.
Systems with severe relu ctor ring damage may exhibit
periodic loss of crankshaft posit ion, stop delivering a signal,
and then re-sync the crankshaft position.
Systems with slight reluctor ring damage may exhibit no
loss of crankshaft position and no misfire may occur,
however, a DTC may set. Replace the crankshaft as required, refer to 4.6 Crankshaft
and Main Bearings.
Refer to 6C1-2 Engine Management – V6 – Diagnostics to
check for DTCs

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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.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–66
Page 6A1–66
3 Minor Service Operations
ATTENTION
The V6 engine is a combination of numerous components, containing machined, honed, polished and lapped
surfaces manufactured on the latest, high technology production equipment. Many of the components
contain tolerances measured in thousa ndths of a millimetre. Consequently, when any e ngine component is to
be serviced, care and cleanliness are extremely important.
Prior to re-assembly of the engine, all components mu st be cleaned and inspected in accordance with the
relevant clean and inspect procedur es throughout this Section, and repl aced or repaired where required.
In addition to cleaning and inspecting components, a liberal coating of engine oil should be applied to friction
surfaces during assembly to protect and lubr icate the surfaces on initial operation.
When performing any service operation, it should be understood that correct cleaning and protection of
machined surfaces and friction areas is part of the repair procedure. This is considered standard workshop
practice, even if not specifically stated. Torque va lues must be used as specified during reassembly to
ensure correct retention of all components.
Through out this section, fastener torque wrench sp ecifications may be accompanied with the following
identification marks:
■ Fasteners must be replaced after loosening.
Fasteners either have micro encapsulated sealant a pplied or incorporate a mechanical thread lock and
should only be re-used once. If in doubt, replacement is recommended.
If one of these identification marks is present alongs ide a fastener torque wrench specification, the
recommendation regarding that fastener must be adhered to.
3.1 Engine Oil
The procedure outlined below is typically the same for both rear wheel drive and all wheel drive vehicles.
Check
The following procedure is applicable to both rear wheel and all wheel drive vehicles
1 Run the engine to bring it to normal operating temperature.
2 Park the vehicle on a level surface. A vehicle that is not level will affect the accuracy of the level reading.
3 Stop the engine and wait 5 to 10 minutes to a llow the oil to drain back into the oil pan.
4 Remove the oil level indicator (1) and wipe clean.
5 Insert the indicator, ens uring it is fully seated.
6 Slowly remove the indicator to avoid smearing. Hold it horizontally or with lower end slightly down to avoid
oil running along indicator.
7 Observe the oil level where it passes over the centre
line of the indicator.
8 If the level is lower than the Add mark (2), add enough oil to the engine to reach the Upper mark (3).
Do not add too much oil as the reading should never
be above the Upper mark.
NOTE
When topping up the oil, allow approximately 5
to 10 minutes for the added oil to fully drain into
the oil pan.
Figure 6A1 – 23

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–227
Page 6A1–227
2 Measure the seat width on the valve face (1) using a
correct scale.
CAUTION
The seat contact area must be at least
0.5 mm from the outer diameter (margin) of
the valve. If the contact area is too close to
the margins, the seat must be reconditioned
to move the contact area away from the
margin.
3 Compare the measurements with the specifications,
refer to 5 Specifications .
4 If the seat widths are a cceptable, check the valve
seat roundness, refer to Valve Seat Roundness
Measurement Procedure in this Section.
5 If the seat width is not acceptable, grind the valve
seat to bring the width back to specification. Correct
valve seat width is critical to providing the correct
amount of valve heat dissipat ion, refer to Valve and
Seat Reconditioning Procedure in this Section.


Figure 6A1 – 383
Valve Seat Roundness Measurement Procedure
1 Measure the valve seat roundness using a dial indicator a ttached to a tapered pilot installed in the guide. The pilot
should have a slight bind w hen installed in the guide.
CAUTION
The correct size pilot must be used. Do not
use adjustable diameter pilots. Adjustable
pilots may damage the valve guides.
2 Compare your measurements with the specifications, refer to 5 Specifications.
3 If the valve seat exceeds the roundne ss specification, grind the valve and valve seat, refer to Valve and Seat
Reconditioning Procedure in this Section.
4 If new valves are being used, the valv e seat roundness must be within 0.05 mm.
Valve Margin Measurement Procedure
1 Measure the valve margin using an appropriate scale.
2 Refer to 5 Specifications for minimum valve margin
and compare them to your measurements.
3 If the valve margins are beyond specification, replace the valves.
4 If the valve margins are within specification and do not require refacing, test the valve for seat
concentricity, refer to Valve-to-Seat Concentricity
Measurement Procedure in this Section.


Figure 6A1 – 384

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Engine Mechanical – V6 Page 6A1–228
Page 6A1–228
Valve-to-Seat Concentricity Measurement Procedure
Checking the valve-to-seat concentricity determines whether the valve and seat are sealing correctly.
Measure the valve face and the valve s eat to ensure correct valve sealing.
1 Coat the valve face lightly with blue dye (3).
2 Install the valve in the cylinder head.
3 Turn the valve against the seat with enough pressure to wear off the dye.
4 Remove the valve from the cylinder head.
5 Inspect the valve face.
NOTE
• If the valve face is concentric, providing a
correct seal, with the valve stem, a continuous
mark (1) will be made around the entire face (2).
• The wear mark must be at least 0.5 mm from
the margin of the valve. If the wear mark is too
close to the margin, the seat must be
reconditioned to move the contact area away
from the margin.
• If the face is not concentric with the stem, the
mark will not be continuous around the valve
face. The valve should be refaced or replaced
and the seat must be reconditioned, refer to
Valve and Seat Reconditioning Procedure in
this Section.

Figure 6A1 – 385
Valve and Seat Reconditioning Procedure
If the valve seat width, roundness or conc entricity are beyond specifications, grind the seats in order to ensure correct
heat dissipation and prevent the bu ild up of carbon on the seats.
If valve seat reconditioning is required, reface the valve face, unless a new valve is used.
1 Grind the valve seats (2) to the correct angle specification, refer to 5 Specifications.
2 Using the correct angle specification, grind and
relieve the valve seats (1) to correctly position the
valve seating surface (2) to the valve.
3 Using the correct angle specification, grind and
undercut the valve seats (3) to narrow the valve seat
widths to the specifications, refer to 5 Specifications.
4 If the original valve is being used, grind the valve to the specifications, refer to 5 Specifications. Measure
the valve margin again after grinding, refer to Valve
Margin Measurement Procedure in this Section.
Replace the valve if the margin is out of specification.
New valves do not require grinding.
5 When grinding the valves and seats, grind off as little material as possible. Cutti ng valve seat results in
lowering the valve spring pressure.
6 Install the valve in the cylinder head.

Figure 6A1 – 386
CAUTION
If using refaced valves, lap the valves into the
seats with a fine grinding compound. The
refacing and reseati ng operations should
leave the refinished surfaces smooth and true
so that minimal lapping is required. Excessive
lapping will groove the valve face and prevent
a good seat when hot.

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