2007 ISUZU KB P190 air suspension

Engine Mechanical – V6 Page 6A1–45

Step Action Yes No
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 torque specification as provided in
provided in 6. Torque W rench 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, refer 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
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, seized pulley or a faulty accessory drive component.
Diagnostic Aids
If the noise is intermittent, confirm the accessory drive components by varying their loads, making sure they are operated
to their maximum capacity. An overcharged A/C system, restrictions in the power steering pressure circuit or a faulty
generator or coolant pump are likely causes 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 the 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 seized bearing. W ith the belt removed, test the bearings in the accessory drive components 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 routed incorrectly and may be turning an accessory drive
component in the wrong direction.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–188

22 Disconnect the EVAP valve outlet tube, (1) from the
upper intake manifold (2).
23 Remove the four long bolts, (3) attaching the upper intake manifold, (2) to the cylinder heads and lower
intake manifold.
Figure 6A1 – 324
23 Remove the six bolts, (1) attaching the lower intake manifold (2), then remove the manifold from the
engine.
24 Remove the following from the engine and engine compartment :
• Lower intake manifold to cylinder head gasket
• The Heater hose
• The Air Cleaner assembly

Figure 6A1 – 325
25 Remove the transmission support (1).
26 Remove the front and rear propeller shafts, (4W D Only), refer to 4C1 Front W heel Drive and 4C2 Drive
Line (For 4W D Vehicles).
27 Remove the front torsion bar springs, refer to 3C Suspension.

Figure 6A1 – 326

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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.

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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

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–243
Page 6A1–243
22 Disconnect the EVAP valve outlet tube, (1) from the
upper intake manifold (2).
23 Remove the four long bolts, (3) attaching the upper intake manifold, (2) to the cylinder heads and lower
intake manifold.

Figure 6A1 – 414
23 Remove the six bolts, (1) attaching the lower intake manifold (2), then remove the manifold from the
engine.
24 Remove the following from the engine and engine compartment :
• Lower intake manifold to cylinder head gasket
• The Heater hose
• The Air Cleaner assembly


Figure 6A1 – 415
25 Remove the transmission support (1).
26 Remove the front and rear propeller shafts, (4WD Only), refer to Section 4C1 Front Wheel Drive and
Section 4C2 Drive Line (For 4WD Vehicles).
27 Remove the front torsion bar springs, refer to Section 3C Suspension .


Figure 6A1 – 416

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ISUZU KB P190 2007