6E–64 ENGINE DRIVEABILITY AND EMISSIONS
– Are there areas subjected to vibration ormovement (engine, transmission or
suspension)?
– Are there areas exposed to moisture, road salt or other corrosives (battery acid, oil or other
fluids)?
– Are there common mounting areas with other systems/components?
– Have previous repairs been performed to wiring, connectors, components or mounting areas
(causing pinched wires between panels and
drivetrain or suspension components without
causing and immediate problem)?
– Does the vehicle have aftermarket or dealer- installed equipment (radios, telephone, etc.)
Step 2: Isolate the problem
At this point, you should have a good idea of what could
cause the present condition, as well as could not cause
the condition. Actions to take include the following:
• Divide (and separate, where possible) the system or circuit into smaller sections
• Confine the problem to a smaller area of the vehicle (start with main harness connections while removing
panels and trim as necessary in order to eliminate
large vehicle sections from further investigation)
• For two or more circuits that do not share a common power or ground, concentrate on areas where
harnesses are routed together or connectors are
shared (refer to the following hints)
Hints
Though the symptoms may vary, basic electrical failures
are generally caused by:
• Loose connections: – Open/high resistance in terminals, splices,connectors or grounds
• Incorrect connector/harness routing (usually in new vehicles or after a repair has been made):
– Open/high resistance in terminals, splices, connectors of grounds
• Corrosion and wire damage:
– Open/high resistance in terminals, splices,connectors of grounds
• Component failure: – Opens/short and high resistance in relays,modules, switches or loads
• Aftermarket equipment affecting normal operation of other systems
You may isolate circuits by:
• Unplugging connectors or removing a fuse to separate one part of the circuit from another part
• Operating shared circuits and eliminating those that function normally from the suspect circuit
• If only one component fails to operate, begin testing at the component
• If a number of components do no operate, begin tests at the area of commonality (such as power sources,
ground circuits, switches or major connectors)
What resources you should use
Whenever appropriate, you should use the following
resources to assist in the diagnostic process:
• Service manual
• Technical equipment (for data analysis)
• Experience
• Technical Assistance
• Circuit testing tools
5d. Intermittent Diagnosis
By definition, an intermittent problem is one that does
not occur continuously and will occur when certain
conditions are met. All these conditions, however, may
not be obvious or currently known. Generally,
intermittents are caused by:
• Faulty electrical connections and wiring
• Malfunctioning components (such as sticking relays, solenoids, etc.)
• EMI/RFI (Electromagnetic/radio frequency interference)
• Aftermarket equipment
Intermittent diagnosis requires careful analysis of
suspected systems to help prevent replacing good
parts. This may involve using creativity and ingenuity to
interpret customer complaints and simulating all
external and internal system conditions to duplicate the
problem.
What you should do
Step 1: Acquire information
A thorough and comprehensive customer check sheet
is critical to intermittent problem diagnosis. You should
require this, since it will dictate the diagnostic starting
point. The vehicle service history file is another
source for accumulating information about the
complaint.
Step 2: Analyze the intermittent problem
Analyze the customer check sheet and service history
file to determine conditions relevant to the suspect
system(s).
Using service manual information, you must identify,
trace and locate all electrical circuits related to the
malfunctioning system(s). If there is more than one
system failure, you should identify, trace and locate
areas of commonality shared by the suspect circuits.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–40
Cause Correction
W orn valve guides and or valve stems. Inspect and repair valves and valve guides as required,
refer to 3.22 Cylinder Head Assembly.
W orn or damaged valve stem oil seal. Replace valve stem oil seals as required, refer to 3.22
Cylinder Head Assembly.
Piston rings broken, worn or not seated correctly. Allowing adequate time for the piston rings to seat correctly,
replace piston rings as required, refer to 4.5 Pistons, Pins,
Rings, Connecting Rods and Big-end Bearings.
Piston rings incorrectly installed or not matched to cylinder
bore oversize. Replace piston rings as required, refer to 4.5 Pistons, Pins,
Rings, Connecting Rods and Big-end Bearings.
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 valley 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 repairing or replacing the faulty component or resealing the gasket surface. However,
once a leak is identified it is important to determine and repair the cause as well as the leak itself.
Locating and Identifying the Leak
Inspect the leaking fluid and determine whether 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.
W hen performing the visual inspection:
1 Bring the vehicle to the normal operating temperature.
2 Park the vehicle over a large sheet of paper or other clean surface.
3 Leave the vehicle idling for 2-3 minutes, then check for dripping fluid.
4 If required, identify the type of fluid leaking 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 kilometres 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 entire engine and surrounding components.
2 Apply an aerosol type powder (e.g. foot 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 viewing 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 available equivalent is available to technicians to aid in
engine oil leak diagnosis. W hen using a black light and die kit for 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.
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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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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 6A1–253
Page 6A1–253
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 revers e 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 co rrect torque specification.
Engine ground connector bolt
torque specificat ion ............................................ 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 specif ication ................... 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 corre ct quantity and grade of coolant, refer to Section 6B1 Engine Cooling – V6.
4 Check transmission fluid level, replenishing as required, using the specified lubricant for the transmission fitted,
refer to Section 7C1 Automatic – 4L60E – General Information .
5 Disable the ignition system, refer to Section 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 t he engine and listen for any unusual noises.
8 Check the vehicle oil pressure gauge or warning indica tor and confirm the engine has acceptable oil pressure. If
required, install an oil pressure gauge and m easure 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 wh ile the engine is running, correcting as required.
12 Perform a final inspection for correct engine oil and coolant levels.
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ISUZU KB P190 2007
Engine Cooling – V6 Engine Page 6B1–53
NOTE
Should the spring clip or the O-ring seal in the
quick connect fitting be damaged during the line
removal process, then the complete fitting must
be replaced.
Reinstall
1 Remove the plugs installed in the transmission cooler line and hose openings and wipe all exposed parts
with a clean shop rag.
• Smear clean automatic transmission fluid on
each cooler line end, then push into the radiator
quick connect fittings. As a security check gently
pull on the connector to ensure correct
engagement.
• As a security check, push and clip each
verification disc into place over the quick-
connect fittings. If difficulty is experienced,
repeat the installation process until the
verification disc can be clipped into place over
the radiator quick-connect fitting.
If the verifier disc does not clip into place,
the quick-connect fitting is not engaged,
rectify this before proceeding.
• Snap the outlet cooler line (4) in the clip (5) of
the radiator fan shroud
• At the transmission end, again clean the line
ends and proceed as detailed in step 2. As a
further security check ensure that each
verification disc can be pushed into place over
the quick connect fitting. If difficulty is
experienced, then the line has not been
completely installed. Remove and repeat the
installation process again until the verification
disc can be clipped into place over the
transmission quick connect fitting
• Ensure that all line clamps are fitted correctly
and that the lines and hoses are correctly routed
and free of obstructions
• Tighten the screw attaching the cooler lines
bracket to the correct torque specifications
• If required, top up the transmission fluid level
(cold)
• Start the engine and check for any fluid leak at
the fittings. If a leak is found, stop the engine
and rectify the leak
Figure 6B1 – 61
Transmission cooler lines bracket
attaching screw torque specification ..................23.0 Nm
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ISUZU KB P190 2007
Engine Cooling – V6 Engine Page 6B1–56
Reinstall
Installation of the radiator is the reverse of removal procedures, noting the following points:
1 Before installing radiator, inspect core to ensure that there is no foreign matter in core fins. Clean out between core fins with compressed air, blowing from rear to front.
2 If the vehicle is fitted with an automatic transmission, remove plugs from the removed cooling pipe ends and the two quick connect fittings.
3 After wiping cooler line ends and smearing clean automatic transmission fluid over each flared line end, push into the quick connect fitting to engage. As a security check, tug on each line to ensure correct engagement.
4 Check the transmission fluid level. Refer to the following references as required:
• 7C4 Automatic Transmission
• 4L60E On-vehicle Servicing
5 Install the following hoses:
a. Lower radiator hose, securing with the hose clamp.
b. Upper radiator hose, securing with the hose clamp.
6 Install the radiator cooling fan and shroud assembly. Refer to 3.13Cooling Fan and Shroud Assembly in this Section. Ensure that electrical connectors and the transmission cooler lines are seated correctly in the integral
retainer clips before install upper radiator shroud.
7 Refill cooling system. Refer to 3.3 Draining and Filling Cooling System in this Section.
8 Check for coolant leaks. Refer to 3.7 Pressure Testing in this Section.
9 Reconnect battery ground lead. Refer to 8A Electrical Body & Chassis.
10 Check cooling fan operation. Refer to 6C1-2 Engine Management Diagnostics. Also check for correct rotational direction of cooling fan.
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ISUZU KB P190 2007
Engine Cooling – V6 Engine Page 6B1–63
4.5 Problems Not Requiring Disassembly of
Cooling System
1 Large obstructions blocking radiator or condenser airflow.
• Auxiliary oil coolers
• License plate
• Obstruction of radiator grille, for example, driving lights or mud
2 Loose, damaged or missing air chute side panels.
3 Missing or damaged air baffle.
4 Cracked or loose coolant recovery system hose.
5 Leaking heater component such as the heater core or water valve.
4.6 Problems Requiring Disassembly of Cooling System
1 Damaged cooling fan or faulty motor operation.
2 Pressure test cooling system.
3 Defective coolant pump.
• Eroded or broken impeller vanes
• Failed bearing or seal – check for shaft or bearing end play
4 Internally blocked radiator core.
5 Obstruction of coolant recovery system.
6 Internal system leaks.
• Head gaskets
• Cracked cylinder block
• Engine front cover
• Intake manifold gaskets
7 Blocked coolant passages in cylinder heads or block – remove cylinder heads and check.
4.7 Black Light and Dye Leak Diagnosis Method
It is strongly recommended that this diagnostic method be used to diagnose fluid leaks. This method is a proven and
reliable method that identifies the specific leak source.
The black light kit can be used for the leak detection of a number of fluids, when used with the appropriate tracer dye.
Examples are: Coolant, Engine Oil, Automatic Transmission Fluid and Air Conditioning Refrigerant (R134A).
The following is a summary of the steps involved in detecting a cooling system fluid leak using black light and dye:
1 Pour specified amount of dye into the cooling system via the coolant filler cap on the outlet housing. Refer 3.1 Service Notes in this Section.
2 Road test the vehicle under normal operating conditions.
3 Direct the light towards the suspect area. The fluid leak will appear as a brightly coloured path leading from the source.
4 Repair fluid leak and recheck to ensure that leak has been rectified.
5 Refer to the manufacturer’s directions when using this method.
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ISUZU KB P190 2007