2007 ISUZU KB P190 indicator

6E–232 ENGINE DRIVEABILITY AND EMISSIONS
SYMPTOM DIAGNOSIS
PRELIMINARY CHECKS
Before using this section, perform the “On-Board
Diagnostic (OBD) System Check” and verify all of the
following items:
• The engine control module (ECM) and malfunction indicator lamp (MIL = Check Engine Lamp) are
operating correctly.
• There are no Diagnostic Trouble Code(s) stored.
• Tech 2 data is within normal operating range. Refer to Typical Scan Data Values.
• Verify the customer complaint and locate the correct symptom in the table of contents. Perform the
procedure included in the symptom chart.
VISUAL/PHYSICAL CHECK
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time. This check should include the following items:
• ECM grounds for cleanliness, tightness and proper location.
• Vacuum hoses for splits, kinks, and proper connection, shown on the “Emission Control System
Schematics”. Check thoroughly for any type of leak or
restriction.
• Air intake ducts for collapsed or damaged areas.
• Air leaks at throttle body mounting area, manifold absolute pressure (MAP) sensor and intake manifold
sealing surfaces.
• Ignition wires for cracking, harness, and carbon tracking.
• Wiring for proper connections, pinches and cuts.
INTERMITTENT
Important: An intermittent problem may or may not turn
on the malfunction indicator lamp (MIL) or store a
Diagnostic Trouble Code. Do NOT use the Diagnostic
Trouble Code (DTC) charts for intermittent problems.
The fault must be present to locate the problem.
Most intermittent problems are cased by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions.
• Poor mating of the connector halves or a terminal not fully seated in the connector (backed out).
• Improperly formed or damaged terminal.
• All connector terminals in the problem circuit should be carefully checked for proper contact tension.
• Poor terminal-to-wire connection. This requires removing the terminal form the connector body to
check.
• Ignition coils shorted to ground and arcing at ignition wires or plugs. • MIL (Check Engine Lamp) wire to ECM shorted to
ground.
• Poor ECM grounds. Refer to the ECM wiring diagrams.
Road test the vehicle with a Digital Multimeter
connected to a suspected circuit. An abnormal voltage
when the malfunction occurs is a good indication that
there is a fault in the circuit being monitored.
Using Tech 2 to help detect intermittent conditions. The
Tech 2 has several features that can be used to located
an intermittent condition.
An intermittent MIL (Check Engine Lamp) with no stored
Diagnostic Trouble Code may be caused by the
following:
• Ignition coil shorted to ground and arcing at ignition wires or plugs.
• MIL (Check Engine Lamp) wire to ECM short to ground.
• Poor ECM grounds. Refer to the ECM wiring diagrams.
Check for improper installation of electrical options such
as light, cellular phones, etc. Check all wires from ECM
to the ignition control module for poor connections.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in Electrical Diagnosis).
If problem has not been found, refer to ECM connector
symptom tables.
• Check the “Broadcast Code” of the ECM, and compare it with the latest Isuzu service bulletins and/
or Isuzu EEPROM reprogramming equipment to
determine if an update to the ECM’s reprogrammable
memory has been released.
To check the “Broadcast Code”, connect the Tech 2,
then look for “ID info.” then select “Broadcast Code”.
This should display a 4 character code, such as “XBYA”
(example only).
This identifies the contents of the reprogrammable
software and calibration contained in the ECM.
If the “Broadcast Code” is not the most current
available, it is advisable to reprogram the ECM’s
EEPROM memory, which may either help identify a
hard-to find problem or may fix the problem.
The Service Programming System (SPS) will not allow
incorrect software programming or incorrect calibration
changes.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–3

Definition .......................................................................................................................................................... 50
Diagnostic Aids................................................................................................................................................. 50
Test Description ............................................................................................................... ................................ 50
Diagnostic Table............................................................................................................................................... 51
Drive Belt Excessive Wear ...................................................................................................... ............................ 51
Definition .......................................................................................................................................................... 51
Diagnostic Aids................................................................................................................................................. 52
Test Description ............................................................................................................... ................................ 52
Diagnostic Table............................................................................................................................................... 52
Accessory Drive Belt Tensioner Diagnosis ....................................................................................... ................ 52
Diagnostic Table............................................................................................................................................... 52
3 Minor Service Operations ....................................................................................................... .............53
3.1 Engine Oil ............................................................................................................................................................. 54
Check .................................................................................................................................................................... 54
Replace ........................................................................................................................ ......................................... 54
Pressure Check ................................................................................................................. ................................... 55
3.2 Oil Filter Cartridge ............................................................................................................................................... 56
Replace ................................................................................................................................................................. 56
3.3 Oil Filter Adaptor............................................................................................................. ..................................... 57
Remove ................................................................................................................................................................. 57
Reinstall ................................................................................................................................................................ 57
3.4 Oil Level Indicator Tube ....................................................................................................... ............................... 58
Remove ............................................................................................................................................................ 58
Reinstall ........................................................................................................................................................... 58
3.5 Accessory Drive Belt ........................................................................................................... ................................ 59
RWD Vehicle ......................................................................................................................................................... 59
Remove ............................................................................................................................................................ 59
Reinstall ........................................................................................................................................................... 59
3.6 Accessory Drive Belt Idler Pulley .............................................................................................. ......................... 60
Remove ............................................................................................................................................................ 60
Reinstall ........................................................................................................................................................... 60
3.7 Accessory Drive Belt Tensioner Assembly ........................................................................................ ............... 61
Remove ............................................................................................................................................................ 61
Reinstall ........................................................................................................................................................... 61
3.8 Power Steering Pump Bracket .................................................................................................... ........................ 62
Remove ................................................................................................................................................................. 62
Reinstall ................................................................................................................................................................ 62
3.9 Upper Intake Manifold.......................................................................................................... ................................ 62
Remove ................................................................................................................................................................. 63
Disassemble ......................................................................................................................................................... 66
Clean ..................................................................................................................................................................... 66
Inspect .................................................................................................................................................................. 66
Reassemble .......................................................................................................................................................... 67
Reinstall ...................................................................................................................... .......................................... 67
3.10 Intake Manifold Assembly – Complete............................................................................................ ................... 68
Remove ................................................................................................................................................................. 68
Disassemble ......................................................................................................................................................... 72
Clean ..................................................................................................................................................................... 73
Inspect .................................................................................................................................................................. 73
Reassemble .......................................................................................................................................................... 74
Reinstall ...................................................................................................................... .......................................... 74
3.11 Exhaust Manifold Assembly ...................................................................................................... ......................... 75
Remove ................................................................................................................................................................. 75
Inspect .................................................................................................................................................................. 77
Reinstall ................................................................................................................................................................ 77
3.12 Camshaft Cover ................................................................................................................. .................................. 79
Remove ................................................................................................................................................................. 79
Clean and Inspect .............................................................................................................. .................................. 81

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–39

2.16 Cylinder Leakage Test
A leakage test may be performed to measure cylinder/combustion chamber leakage. High cylinder leakage may indicate
one or more of the following:
• worn or burnt valves,
• broken valve springs,
• stuck valve lifters,
• incorrect valve lash/adjustment,
• damaged piston,
• worn piston rings,
• worn or scored cylinder bore,
• damaged cylinder head gasket,
• cracked or damaged cylinder head, or
• cracked or damaged engine block.

1 Disconnect the battery ground negative cable.
2 Remove the spark plugs from all cylinders, refer to 6C1-3 Engine Management – V6 – Service Operations.
3 Rotate the crankshaft to place the piston in the cylinder being tested at top dead centre (TDC) of the compression stroke.
4 Install a commercially available cylinder head leak down tester into the spark plug hole.
NOTE
If required, hold the crankshaft balancer bolt to
prevent the engine from rotating.
5 Apply shop air pressure to the cylinder head leak down tester and adjust according to the manufacturers instructions.
6 Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions:
• air leakage sounds at the throttle body or air inlet duct that may indicate a worn or burnt intake valve or a
broken valve spring,
• air leakage sounds at the exhaust system tailpipe that may indicate a worn or burnt exhaust valve or a broken
valve spring,
• air leakage sounds from the crankcase, oil level indicator tube, or oil fill tube that may indicate worn piston
rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block or a damaged cylinder
head, or
• air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket.
7 Perform the leakage test on the remaining cylinders and record the values.
2.17 Engine Oil Consumption Diagnosis
Definition
Excessive oil consumption (not due to leaks) is the use of 3 litres or more of engine oil within 10,000 kilometres. Prior to
performing oil pressure testing, a preliminary inspection of the vehicle should be performed. During the preliminary visual
inspection, the following likely causes of excessive oil usage should be investigated.
Cause Correction
External oil leaks. Refer to 2.18 Engine Oil Leak Diagnosis.
Incorrect oil level or reading of the oil level indicator. Check for the correct oil level, refer to 3.1 Engine Oil.
Incorrect oil viscosity. Replace the engine oil, using the recommended SAE grade
of engine oil, refer to 3.1 Engine Oil.
Continuous high-speed driving or severe usage. Service vehicle more frequently, refer to 0B Lubrication and
Service.
Crankcase ventilation system restricted or malfunctioning. Repair or replace crankcase ventilation system components as required, refer to 6C1-3 Engine Management – V6 –
Service Operations.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–54

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 allow the oil to drain back into the oil pan.
4 Remove the oil level indicator (1) and wipe clean.
5 Insert the indicator, ensuring 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
Replace
NOTE
• Quicker and more complete draining will
occur if the engine oil is at normal operating
temperature. However, care must be taken to
avoid scalding from the hot oil.
• It recommended the oil filter be changed at
each engine oil change, refer to 3.2 Oil
Filter.
1 Remove the oil fill cap.
2 To ensure complete draining of the oil pan, raise the front and rear of the vehicle to maintain a level attitude. If not using a hoist, support the vehicle with safety stands, refer to 0A General Information.
3 Clean any foreign material from around the oil drain plug and place a suitable, clean drain tray under the engine.

The oil may be hot. Avoid contact with the oil.
Ensure that eyes and skin are protected.
4 Remove the drain plug (1), taking care to avoid scalding from the hot oil. Allow the oil to drain.
5 Clean and inspect the drain plug threads. If damaged, replace the drain plug.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–58

3.4 Oil Level Indicator Tube
Remove
1 Remove the oil level indicator from the oil level indicator tube.
2 Remove the bolt (2) attaching the oil level indicator tube (1) and engine wiring harness retaining bracket.
3 W ithdraw the oil level indicator tube from the oil pan.
4 Remove and discard the o-ring at the bottom of the oil level indicator tube.
Figure 6A1 – 28
Reinstall
Reinstallation of the oil level indicator tube is the reverse of the removal procedure, noting the following:
1 Install a new oil level indicator o-ring.
2 Ensure the attaching bolt passes through the engine wiring harness retaining bracket.
3 Tighten bolt to the correct torque specification.
Oil level indicator tube attaching bolt
torque specification ...................................8.0 – 12.0 Nm


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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–76

2 Remove the oxygen sensor harness connector (1)
from the retaining bracket.
3 Disconnect the oxygen sensor wiring harness connector from the engine wiring harness connector
(2).
4 Unclip the oxygen sensor wiring harness retaining clip and move aside.
5 For the left-hand side: Remove the oil level indicator tube.
6 Raise the front of the vehicle and place on stands, refer to 0A General Information.
7 W orking from under the vehicle, remove the two exhaust manifold to exhaust pipe flange nuts, refer to
6F Exhaust System - V6 - V6.
Figure 6A1 – 56
8 Remove the three bolts attaching the exhaust manifold outer heat shield (1) to the exhaust manifold
(2).

Figure 6A1 – 57
9 Progressively loosen the seven exhaust manifold attaching bolts (2), working from the outside to the
centre and then remove the bolts.
10 Manoeuvre the exhaust manifold (3), away from the cylinder head.
11 Remove and discard the exhaust manifold to cylinder head gasket.



Figure 6A1 – 58

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–151

Camshaft Measurement
1 W ith the camshaft (1) in a suitable fixture (2),
measure the camshaft for wear.
2 For camshaft measurement, refer to the following specifications, 5 Specifications.

NOTE
If the camshaft measures outside the specified
range, replace the camshaft.
CAUTION
No machining of the camshaft is allowed.
Figure 6A1 – 247
3 Measure the camshaft (2) journals for diameter and out-of-round using an outside micrometer (1).

Figure 6A1 – 248
4 Measure the camshaft runout using a dial indicator (1).

Figure 6A1 – 249

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–152

5 Measure the camshaft thrust width for wear using a
depth micrometer (A).

Figure 6A1 – 250
6 Measure the camshaft thrust wall surface for runout using a dial indicator (1).

Figure 6A1 – 251
7 Measure the camshaft lobes for wear using a dial indicator (1).

Figure 6A1 – 252

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ISUZU KB P190 2007