Isuzu Trooper (2000 year). Manual - part 191

6A–49

ENGINE MECHANICAL

Cylinder Head

Cylinder Head and Associated Parts

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Legend

(1) Spark Plug
(2) Cylinder Head Bolt
(3) Camshaft Drive Gear Pulley Fixing Bolt
(4) Camshaft Drive Gear Pulley
(5) Camshaft Bearing Cap Fixing Bolt
(6) Camshaft Bearing Cap
(7) Camshaft Exhaust

(8) Camshaft Intake
(9) Retainer Fixing Bolt

(10) Retainer Assembly

(11) Tappet with Shim

(12) Split Collar
(13) Valve Spring and Spring Upper Seat
(14) Valve

6A–50

ENGINE MECHANICAL

Disassembly

NOTE:

D

During disassembly, be sure that the valve train
components are kept together and identified so that
they can be reinstalled in their original locations.

D

Before removing the cylinder head from the engine
and before disassembling the valve mechanism,
perform a compression test and note the results.

1. Remove camshaft drive gear pulley fixing bolt (3),

then pulley (4).

2. Remove camshaft bearing cap fixing bolt (5),

camshaft bearing cap (6), then camshaft exhaust (7),
and intake side (8).

3. Remove tappet with shim (11).
4. Use the J–8062 valve spring compressor and

J–42898 valve spring compressor adapter to remove
the split collar (12), valve spring with upper seat (13)
and valve (14).

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5. Remove spark plug (1).

CAUTION: Do not remove the spark plugs when the
head and plugs are hot. Clean dirt and debris from
spark plug recess areas before removal.

Clean

Cylinder head

Carefully remove all varnish, soot and carbon from the
bare metal. Do not use a motorized wire brush on any
gasket sealing surface.

Inspection and Repair

1. Cylinder head gasket and mating surfaces for leaks,

corrosion and blow–by. If the gasket has failed,
determine the cause.
– Insufficient torque on head bolts.
– Improper installation
– Loose or warped cylinder head
– Missing dowel pins
– Warped case surface

2. Cylinder head for cracks, especially between valve

seats and in the exhaust ports.

3. Cylinder head deck for corrosion, sand particles in

head and porosity.

CAUTION:

D

Do not attempt to weld the cylinder head. Replace
it.

D

Do not reuse cylinder head bolts.

4. Cylinder head deck, common chamber and exhaust

manifold mating surfaces for flatness. These
surfaces may be reconditioned by milling. If the
surfaces are “out of flat” by more than specification,
the surface should be ground to within specifications.
Replace the head if it requires machining beyond the
repairable limit.

Head surface and manifold surface
Standard: 0.05 mm (0.002 in) or less
Warpage limit: 0.2 mm (0.0079 in)
Maximum Repairable limit: 0.2 mm (0.0079 in)

Head height
Standard height : 133.2 mm (5.2441 in)
Warpage limit : 0.2 mm (0.0079 in)
Maximum Repairable limit : 133.0 mm (5.2362 in)

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5. Water jacket sealing plugs seating surfaces.

6A–51

ENGINE MECHANICAL

Reassembly

1. Install Spark plug and tighten all the spark plugs to

specified torque.

Torque: 18 N·m (13 lb ft)

2. Tighten sub gear setting bolt.

1. Use J–(42686 gear spring lever) to turn sub gear

to right direction until the M5 bolt aligns with the
hole between camshaft driven gear and sub gear.

2. Tighten the M5 bolt to a suitable torque to prevent

the sub gear from moving .

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3. Install camshaft drive gear assembly and tighten

three bolts to the specified torque.

Torque: 10 N·m (7.4 lb ft)

4. Install camshaft assembly and camshaft bearing cap,

tighten twenty bolts on one side bank to the specified
torque.
1. Apply engine oil to camshaft journal and bearing

surface of camshaft bearing cap.

2. Align timing mark on intake camshaft (one dot for

right bank, two dots for left bank) and exhaust
camshaft (one dot for right bank, two dots for left
bank) to timing mark on camshaft drive gear (one
dot).

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Legend

(1) Intake Camshaft Timing Gear for Right Bank
(2) Intake Camshaft Timing Gear for Left Bank
(3) Exhaust Camshaft Timing Gear
(4) Discrimination Mark

LI: Left Bank Intake

RI: Right Bank Intake

LE: Left Bank Exhaust

RE: Right Bank Exhaust

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Legend

(1) Right Bank Camshaft Drive Gear
(2) Left Bank Camshaft Drive Gear
(3) Timing Mark on Drive Gear
(4) Dowel Pin

6A–52

ENGINE MECHANICAL

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Legend

(1) Right Bank
(2) Left Bank

(3) Alignment Mark on Camshaft Drive Gear
(4) Alignment Mark on Camshaft
(5) Alignment Mark on Retainer

3. Tighten twenty bolts in numerical order on one

side bank as shown in the illustration.

Torque: 10 N·m (89 lb in)

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5. Tighten bolt for camshaft drive gear assembly pulley

to the specified torque.

Torque: 98 N·m (72 lb ft)