Isuzu KB P190. Manual - part 636

Engine Mechanical – V6 

Page 6A1–65 

 

8 

Disconnect the wiring harness connector from the 
barometric (BARO) pressure sensor (1). 

 

Figure 6A1 – 37 

9 

Disconnect the PCV tube connector (1) from the 
upper intake manifold assembly. 

 

Figure 6A1 – 38 

10 

Remove the bolt (3) attaching the EVAP valve and the 
fuel injector wiring harness connector mounting 
bracket to the upper intake manifold assembly. 

11 

Move the EVAP valve and the fuel injector wiring 
harness connector mounting bracket clear of the upper 
intake manifold assembly. 

12 

Disconnect the PCV fresh air tube (1) from its upper 
intake manifold mounting clip (2). 

 

Figure 6A1 – 39 

Engine Mechanical – V6 

Page 6A1–66 

 

13 

Disconnect the EVAP valve outlet tube (1) from the 
intake manifold (2). 

14 

Remove the four long (3) (165 mm long) and two short 
bolts (4) (70 mm long) attaching the upper intake 
manifold (2) to the cylinder heads and lower intake 
manifold. 

15 

Lift the upper intake manifold (2) clear from the lower 
half and then remove the upper intake manifold from 
the engine. 

16 

Remove and discard the upper to lower intake 
manifold gaskets (5). 

 

 

•  When the upper intake manifold is 

removed, plug each of the lower intake 
runner openings with lint free cloth, to 
stop the entry of foreign material into the 
engine. 

•  Do not reuse the upper to lower intake 

manifold gaskets (5). 

Figure 6A1 –

––

– 40 

17 

Remove the upper and lower intake manifold assembly from the engine. 

18 

Remove lower intake manifold to cylinder head gasket. 

Disassemble 

Remove the following from the upper intake manifold, refer to 6C1-3 Engine Management – V6 – Service Operations: 
• 

BARO sensor and 

• 

Throttle body assembly. 

Clean 

CAUTION

 

Due to the aluminium alloy construction of 
the intake manifold, wire brushes and steel 
scrapers must not be used during the 
cleaning process, as damage to sealing 
surfaces may occur. Use of a wooden or 
plastic scraper is preferred. 

1 

Clean mating surfaces ensuring any gasket material is removed. 

2 

Clean the manifold using a suitable solvent. 

 

Safety glasses must be worn when using 
compressed air. 

3 

Dry the timing components with compressed air. 

Inspect 

1 

Inspect the intake manifold for the following fault conditions: 

Engine Mechanical – V6 

Page 6A1–67 

 

• 

Damaged sealing and mating surfaces. 

• 

Damaged lower intake manifold gasket. 

• 

Damage or excessive debris on the threaded and through holes. 

• 

Cracks or damage to the intake manifold body. 

N O T E  

If the lower intake manifold is cracked or 
damaged, it must be replaced. No welding or 
patching of the intake manifold should be 
performed. 

2 

Place a straight edge (1) across the upper intake 
manifold sealing surface (2). 

3 

Using a feeler gauge (3), measure the clearance 
between the manifold and the straight edge. 

4 

If the clearance between the upper intake manifold 
sealing surface and the straight edge exceeds the 
specified maximum warpage, replace the manifold. 

 

 

Upper manifold maximum 
warpage ............................................................ 0.05 mm 

Figure 6A1 – 41 

5 

Place a straight edge (1) across the lower intake 
manifold sealing surface (2). 

6 

Using a feeler gauge (3), measure the clearance 
between the manifold and the straight edge. 

7 

If the clearance between the lower intake manifold 
sealing surface and the straight edge exceeds the 
specified maximum warpage, replace the manifold. 

 

 

Lower manifold maximum 
warpage ............................................................ 0.05 mm 

Figure 6A1 – 42 

Reassemble 

Reassembly of the upper manifold is the reverse of the disassembly procedure . 

Reinstall 

Reinstallation of the upper intake manifold and the upper and lower intake manifold assembly is the reverse of the 
removal procedure, noting the following: 

1 

Only new gaskets are to be fitted between the upper and lower intake manifolds. 

Engine Mechanical – V6 

Page 6A1–68 

 

CAUTION

 

Tighten the intake manifold bolts in a circular 
pattern starting at the centre bolt and moving 
outward. 

2 

Ensure that all fasteners are tightened to the correct torque specification. 

Upper intake manifold to lower 
intake manifold attaching bolt  
torque specification ............................................23.0 Nm 

Upper intake manifold to  
cylinder head attaching bolt  
torque specification ............................................23.0 Nm 

 

Incorrect wiring connector installation may 
cause component malfunction or component 
damage. 

3 

Ensure all wiring connectors are fully engaged and if applicable, locked in place. 

4 

Ensure all wiring harnesses are correctly routed and attached securely in their retaining clips. 

5 

Ensure that all hoses and pipes are routed correctly and that any retaining clips are correctly installed. 

6 

Start and run the engine to check for correct operation. 

3.10  Intake Manifold Assembly – Complete 

The intake manifold comprises of an upper and lower section. Some service procedures only require the removal of the 
upper intake manifold (e.g. fuel injector/spark plug servicing), while other service procedures require the removal of both 
the upper and lower manifold as a complete assembly (e.g. cylinder head/s). If only the upper intake manifold needs to 
be removed, refer to 3.9 

Upper Intake Manifold. 

Remove 

 

Disconnection of the battery affects certain 
vehicle electronic systems. Refer to 1.1 

 

WARNING, CAUTION and NOTES before 
disconnecting the battery. 

1 

Depressurise the fuel system. 

2 

Disconnect the battery negative terminal.