engine ISUZU KB P190 2007 Workshop Repair Manual

Engine Mechanical – V6 Page 6A1–218
Page 6A1–218
Left-hand Side (Bank 2) Cylinder Head
1 Remove the intake manifold assembly, refer to 3.10 Intake Manifold Assembly – Complete .
2 Remove the exhaust manifold, refer to 3.11 Exhaust Manifold Assembly.
3 Remove the power steering reservoi r and pump mounting brackets, refer to 3.8 Power Steering Pump Bracket.
NOTE
Do not disconnect the power steering pipes
and/or hoses.
4 Remove the oil filter adapter upper bolt. NOTE
Do not remove the oil filter adapter.
5 Remove the engine coolant temper ature (ECT) sensor, refer to Section 6C1-3 Engine Management – V6 – Service
Operations .
6 Remove engine harness ground terminal attach ing bolt from cylinder head, refer to Section 8A Electrical Body &
Chassis .
7 Remove the left-hand bank secondary timing chain, refer to 3.16 Timing Chains, Tensioners, Shoes and Guides.
8 Remove the camshaft position actuators, refer to 3.18 Camshaft Sprocket.
9 Remove the front M8 (1) cylinder head attaching bolt, two places.
10 Remove the cylinder head attaching bolt (2), eight places.
11 Remove the cylinder head (3).


Figure 6A1 – 367
12 Remove and discard the cylinder head gasket (1).


Figure 6A1 – 368

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–219
Page 6A1–219
Disassemble
1 Using an appropriately sized deep socket (1) and a
plastic hammer (2), lightly tap on the valve spring
retainer to loosen the valve collets.


CAUTION
Ensure valve heads will not contact anything
during this step in order to avoid bending or
damage.

Figure 6A1 – 369
CAUTION
Do not compress the valve springs less than
24.0 mm. Contact between the valve spring
retainer and the valve stem oil seal can
cause potential valve stem oil seal damage.

Compressed valve springs (1) have high
tension against the valve spring
compressor (2). Valve springs that are not
correctly compressed by, or are released
from the valve spring compressor can be
ejected from the valve spring compressor
with intense force. Use care when
compressing or releasing the valve spring
with the valve spring compressor and when
removing or installing the valve stem keys.
Failing to use care may cause personal
injury.
2 Compress the valve spring (1) using valve spring compressor Tool No. J-8062 (2) and adaptor Tool No.
EN-46119.


Figure 6A1 – 370

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–220
Page 6A1–220
3 Remove the valve collets using Tool EN-46117 (1).
4 Remove the valve spring compressor (2) and the adapter (3).


Figure 6A1 – 371
5 Remove the valve spring retainer (1).
6 Remove the valve spring (2).


Figure 6A1 – 372
7 Remove the valves (1).


Figure 6A1 – 373

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–221
Page 6A1–221
CAUTION
Never reuse a valve stem oil seal.
8 Remove the valve stem oil seal using Tool No. EN-46116 and discard.
9 Repeat these procedures for the remaining valves.

Figure 6A1 – 374
10 Remove the cylinder head oil gallery expansion plugs (1).


Figure 6A1 – 375
11 Remove the cylinder head coolant threaded plugs (1).


Figure 6A1 – 376

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–222
Page 6A1–222
Clean
CAUTION
Due to the aluminium alloy construction of
the cylinder head, wire brushes and steel
scrapers must not be used during the
cleaning process, as damage to sealing
surfaces may occur. Use a wood or plastic
scraper as an alternative.
1 Remove any old thread sealant, gasket material or seal ant using commercially available plastic or wooden scraper.
2 Clean all cylinder head surfaces with non-corrosive solvent.

Safety glasses must be worn when using
compressed air.
3 Blow out all the oil galleries using compressed air.
4 Remove any carbon deposits fr om the combustion chambers.
5 Clean any debris or build-up from the lifter pockets.
Inspect
Visual Inspection
1 Inspect the cylinder head (1) camshaft bearing surfaces for the following conditions:
• excessive scoring or pitting,
• discoloration from overheating, and
• deformation from excessive wear.
2 If any of the above conditions exist on the camshaft bearing surfaces, replace the cylinder head. Do not
machine the camshaft bearing journals.


Figure 6A1 – 377
3 Inspect the cylinder head for the following: • Cracks, damage or pitting in the combustion chambers.
• Debris in the oil galleries. continue to cl ean the galleries until all debris is removed.
• Coolant leaks or damage to the deck face sealing surfac e. if coolant leaks are present, measure the surface
warpage as described under Cylinder Head M easurement within this Section.
• Burrs or any defects that would degrade the sealing of a new secondar y camshaft chain tensioner gasket.
• Damage to any gasket surfaces.
• Damage to any threaded bolt holes.
• Burnt or eroded areas in the combustion chamber.
• Cracks in the exhaust ports and combustion chambers.
• External cracks in the water passages.
• Restrictions in the intake or exhaust passages.
• Restrictions in the cooling system passages.
• Rusted, damaged or leaking core plugs.
4 If the cylinder head is cracked or damaged, it must be r eplaced. No welding or patching of the cylinder head is
recommended.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–223
Page 6A1–223
Cylinder Head Measurement
NOTE
For all cylinder head and associated component
specifications, refer to 5 Specifications.
Camshaft Journal Clearance
1 Install the camshaft bearing cap in the cylinder head without the camshaft.
2 Install the camshaft cap bolts and tight en to the correct torque specification
Camshaft bearing cap attach ing bolt........ 8.0 – 12.0 Nm.
3 Measure the camshaft bearings using an inside micrometer.
4 Subtract the camshaft journal diam eter from the camshaft bearing diameter. This will provide the running
clearance. If the running clearance exceeds specifications and the camshaft journals are within specification,
replace the cylinder head.
Camshaft Journal Alignment
1 Ensure the camshafts are serviceable, refer to 3.19 Camshaft for measuring procedures.
2 Inspect the cylinder head camshaft bearing surfaces for any imperfections or scratches that could inhibit correct
camshaft clearances. Repair minor imperfections or scratches.
3 Install the camshafts in the cylinder head.
4 Install the camshaft bearing caps.
5 Install the camshaft cap bolts and tighten to the correct torque specification.
Camshaft bearing cap attach ing bolt........ 8.0 – 12.0 Nm.
6 Ensure the camshafts spin freely in the cylinder head. If the camshaft does not run freely, replace the cylinder
head.
Deck Flatness Inspection
1 Ensure the cylinder head decks are clean and free of gasket material.
2 Inspect the surface for any imperfections or scratches
that could inhibit correct cylinder head gasket sealing.
3 Place a straight-edge (1) diagonally across the cylinder head (2) deck face surface.
4 Measure the clearance between the straight-edge
and the cylinder head deck face using a feeler gauge
at four points along the straight-edge.
5 If the warpage is less t han 0.05 mm, the cylinder
head deck surface does not require resurfacing.
6 If the warpage is between 0.05±0.20 mm or any imperfections or scratches that could inhibit correct
cylinder head gasket sealing are present, the cylinder
head deck surface requires resurfacing.
7 If resurfacing is requir ed the maximum amount that
can be removed is 0.25 mm.
8 If the cylinder head deck surface requires more than 0.25 mm material removal the head must be
replaced.

Figure 6A1 – 378

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–224
Page 6A1–224
Valve Guide Measurement
1 Measure the valve stem (1) to-guide (2) clearance.
Excessive valve stem-to-guide clearance may cause
excessive oil consumption and may also cause a
valve to break. Insufficient clearance will result in
noisy and sticky functioning of the valve and will
disturb the engine assembly smoothness.
2 Clamp a dial indicator to the cylinder head at the camshaft cover rail.
3 Locate the dial indicator so the movement of the valve
stem from side to side, crossways to the cylinder
head, will cause a direct mo vement of the indicator
stem. The dial indicator stem must contact the side of
the valve stem just above the valve guide.
4 Drop the valve head about 0.064 mm off the valve seat.
5 Use light pressure when moving the valve stem from side to side to obtain a clearance reading, refer to
5 Specifications .
• If the clearance for the valve is greater than
specified and a new st andard diameter valve
stem will not bring the clearance within
specifications, the valv e guide may be oversized
by 0.075 mm using the valve guide reamer, Tool
No. J 42096 or by 0.375 mm using the valve
guide reamer, Tool No. EN-46120. Two sizes of
oversized valve stems are available for service.
• Valve guide wear at the bottom 10 mm of the
valve guide is not significant enough to affect
normal operation.
• If over sizing the guide does not bring the
clearance within specif ications, replace the
cylinder head.

Figure 6A1 – 379

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–225
Page 6A1–225
Valve Spring Inspection and Measurement
Inspection Procedure
1 Clean the valve springs in solvent.

Safety glasses must be worn when using
compressed air
2 Dry the valve springs with compressed air.
3 Inspect the valve springs for broken coils or coil ends.
Measurement Procedure
1 Use a commercially available valve spring tester to measure the valve spring tension, refer to
5 Specifications .
CAUTION
Do not use shims to increase spring load.
The use of shims can cause the valve spring
to bottom out before the camshaft lobe is at
peak lift.
2 If low valve spring load is found, replace the valve springs.


Figure 6A1 – 380
Valve and Seat Grinding
Valve Cleaning Procedure
CAUTION
Do not use a wire brush on any part of the
valve stem. The valve stem is chrome plated
to provide enhanced wear characteristics.
Wire brushing the stem could remove the
chrome plating.
1 Use soft bristle brush to clean any carbon build-up from the valve head.
2 Thoroughly clean the valve with solvent and wipe dry.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–226
Page 6A1–226
Valve Visual Inspection Procedure
1 Inspect the valve for damage from the head to tip for
the following conditions:
• pitting in the valve seat area (1),
• lack of valve margin (2),
• bending in the valve stem (3),
• pitting or excessive wear in the stem (4),
• worn valve key grooves (5), and
• worn valve tip (6).
2 Replace the valve if any of these conditions exist.


Figure 6A1 – 381
Valve Measurement and Reconditioning Overview
Correct valve service is critical to engine performance. Therefore, all detailed measurement procedures must be followed
to identify components that are out of specification. If the measurement procedures reveal t he valve or valve seat must
be reconditioned, it is critical to perform t he measurement procedures after reconditioning.
Valve Seat Width Measurement Procedure
1 Measure the valve seat (1) width in the cylinder head
using a scale (2).


Figure 6A1 – 382

BACK TO CHAPTER INDEX
TO MODEL INDEX
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

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007