ISUZU TROOPER 1998 Service Repair Manual

6A – 58 ENGINE MECHANICAL
14. Camshaft pulley
1) Align TDC mark with crankshaft pulley and gear
case cover.
2) Set camshaft stopper on the end of intake and
exhaust camshaft.
Camshaft Stopper: 5-8840-2592-0
3) Install key to camshaft and install camshaft
pulley.
4) Apply engine oil to camshaft pulley fixing bolt
and tighten bolt with angular tightening method.
First step: 40 N·m (4.0 kg·m / 29 lb ft)
Second step: 60° to 90°
15. Timing belt
1) Install tensioner and tighten the bolt temporarily.
2) Align timing mark with camshaft pulley timing
mark and timing gear case timing mark.
3) Set No.1 cylinder TDC position.4) Install the timing belt in the following order
camshaft pulley, oil pump pulley, tensioner.
NOTE:
1) It is recommended for easy installation that the belt
be secured with a double clip after it is installed to
each pulley.
2) The “ISUZU” mark should be read from the front of
the engine when installing the timing belt.
5) Install the belt tensioner.
6) Conform not phase difference each pulley.
7) Tension the timing belt with two turns of the
crankshaft.
8) Tighten the tensioner bolt in order A to B to the
specified torque.
Torque: Bolt A 5 N·m (0.5 kg·m/3.6 lb ft)
Bolt B 2 N·m (0.2 kg·m/1.4 lb ft)
Legend
(1) Align Mark
(2) Camshaft Pulley
(3) Timing Belt
(4) Oil Pump Pulley
(5) Bolt B
(6) Tensioner Assy
(7) Tensioner Bolt A
(8) Tensioner Spring
16. CMP sensor bracket
1) Install CMP sensor bracket and tighten bolt to
the specified torque.
Torque: 20 N·m (2.0 kg·m / 14.5 lb ft)
17. Timing belt cover
1) Install timing belt cover and tighten bolt to the
specified torque.
Torque: 9 N·m (0.9 kg·m / 6.5 lb ft)
2) Tighten CMP sensor to the specified torque.
Torque: 9 N·m (0.9 kg·m / 6.5 lb ft)
012RW036
012RW099
1
2
3
8
67
4 5
F06RW055

ENGINE MECHANICAL 6A – 59
18. Crankshaft damper pulley
1) Insert damper pulley with the crankshaft key
groove set on the key.
2) Tighten damper pulley bolt to the specified
torque.
Torque: 220 N·m (22 kg·m / 159 lb ft)19. Cooling fan Assembly
1) Install the cooling fan assembly to the fan pulley,
tighten the nuts to the specified torque.
Torque: 8 N·m (0.8 kg·m / 5.8 lb ft)
20. AC generator drive belt.
1) Temporarily tighten generator fixing bolts and
belt tensioner adjustment plate.
2) Tension the generator drive belt then tighten the
generator fixing bolt.
Torque: 40 N·m (4.0 kg·m / 29 lb ft)
3) Tighten the belt tensioner adjustment plate bolt.
Torque: 20 N·m (2.0 kg·m / 14.5 lb ft)
012RW039
014RW163
012RW032

6A – 60 ENGINE MECHANICAL
VALVE STEM SEAL, VALVE SPRING AND ADJUSTER
REMOVAL
1. Disconnect battery ground cable.
2. Drain engine coolant.
3. Remove the air duct from between air cleaner and
turbocharger.
4. Remove intercooler assembly.
Refer to “Intercooler” in this manual.
5. Remove oil level gauge guide assembly.
6. Disconnect PCV hose.
7. Disconnect EGR vacuum hose.
8. Disconnect harness connectors around the cylinder
head such as the injector, CMP sensor, MAP
sensor, EGR sensor, EVRV, IAT sensor, A/C
compressor, TP stepping motor, TP sensor and fuel
temperature sensor etc.
9. Remove A/C compressor assembly.
10. Remove A/C compressor bracket.
11. Remove generator assembly and take out drivebelt.
12. Remove heat protector, remove exhaust valve
assembly.
13. Remove water cooling hose and lubrication pipe for
turbocharger.
14. Remove turbocharger assembly.
15. Remove hose between thermostat and radiator.
16. Remove noise insulator cover of cylinder head.
NOTE: Do not damage injector harness.
17. Remove high pressure oil pipe.
18. Remove timing belt cover.
19. Remove CMP sensor bracket.
20. Remove timing belt tensioner then remove timing
belt.
21. Remove camshaft pulley.
22. Remove front plate.
23. Remove engine coolant pipe between cylinder
head and water pump.
1
2
3
4
5
6
9
10
7
8
011RW031
Legend
(1) Adjuster
(2) Tappet
(3) Split Collar
(4) Spring Seat Upper
(5) Valve Spring(6) Spring Seat Lower
(7) Valve Stem Seal
(8) Valve Guide
(9) Valve Seat
(10) Valve

ENGINE MECHANICAL 6A – 61
24. Remove fuel pipe between fuel pump and intake
manifold.
25. Remove fuel return pipe from rear of cylinder head.
26. Remove intake manifold assembly.
27. Disconnect glow plug harness and remove glow
plug.
28. Remove cylinder head cover.
29. Remove injector harness connector.
30. Disconnect harness connector from oil pressure
sensor and oil temperature sensor on the oil rail.
31. Remove injector harness assembly.
32. Remove injector clamp.
33. Remove injector is fixed bolts.
34. Remove injector assembly.
35. Remove oil rail.
36. Remove camshaft carrier assembly with camshaft.
37. Remove cylinder head assembly.
38. Disassemble valve spring according to the following
method.
1) Use valve spring compressor then remove split
collars.
2) Valve spring compressor: 5-8840-2441-0
NOTE: Put removed valve spring in order of cylinder
number.
39. Valve stem seal.
1) Use a screwdriver or pliers to remove valve
stem seal.
NOTE: Do not reuse removed valve stem seal.
INSPECTION AND REPAIR
Make the necessary adjustments, repairs and part
replacements if excessive wear or damage is
discovered during inspection.
Valve spring
CAUTION: Visually inspect the valve springs and
replace them if damage or abnormal wear is
evident.
1. Free height
1) Measure the free height of the springs. The
springs must be replaced if the height is below
the specified limit.
Standard: 45.85 mm (1.8051in)
Limit: 43.9 mm (1.7283 in)
2. Squareness
1) Measure the valve spring squareness with a
steel square.
2) Replace the valve springs if the measured value
exceeds the specified limit.
Limit: 1.6 mm (0.063 in)
014rw042
014rs004
014rs005

6A – 62 ENGINE MECHANICAL
3. Spring tension
1) Use a spring tester to compress the springs to
the installed height. Measure the compressed
spring tension.
2) Replace the springs if the measured tension is
below the specified limit.
Standard: 236.0 N (24 kg/53 lb)
Limit: 205.0 N (21 kg/46 lb)Valve Guide
CAUTION: Taking care not to damage the valve seat
contact surface, when removing carbon adhering to
the valve head.
Carefully inspect the valve stem for scratching or
abnormal wear. If these conditions are present, the
valve and the valve guide must be replaced as a set.
1. Valve Guide Clearance
1) Measure the valve stem diameter with a
micrometer.
If the valve stem diameter is less than the
specified limit, the valve and the valve guide
must be replaced as a set.
Diameter of Valve stem:Inlet
Standard: 6.959 – 6.977 mm (0.2740 – 0.2747 in)
Limit: 6.92 mm (0.2724 in)
Diameter of Valve stem:Exhaust
Standard: 6.952 – 6.97 mm (0.2737 – 0.2744 in)
Limit: 6.90 mm (0.2717 in)
2) Measure the inside diameter of the valve guide
with a micrometer.
3) Subtract the measured outer diameter of the
valve stem from the measured inner diameter of
the valve guide.
If the valve exceeds the specified limit, the valve
and the valve guide must be replaced as a set.
Inlet clearance
Standard: 0.023 – 0.053 mm (0.0009 – 0.0021 in)
Limit: 0.19 mm (0.0075 in)
Exhaust clearance
Standard: 0.03 – 0.063 mm (0.0012 – 0.0025 in)
Limit: 0.20 mm (0.0079 in)
014RS006
014RS007

ENGINE MECHANICAL 6A – 63
Valve Guide Replacement
1. Using the special tool, drive out the valve guide
from the combustion chamber side.
Valve guide replacer: 9-8523-1212-0
2. Apply engine oil to the outside of the valve guide.
Using the special tool, drive in a new valve guide
from cylinder head upper face side, and check the
valve guide height.
Valve guide replacer: 9-8523-1212-0
Height: 8.0 mm (0.315 in)
NOTE: If the valve guide has been removed, both the
valve and the valve guide must be replaced as a set.
Valve Thickness
1. Measure the valve thickness.
2. If the measured value is less than the specified
limit, the valve and the valve guide must be
replaced as a set.
Inlet
Standard: 1.2 mm (0.0472 in)
Limit: 1.1 mm (0.0433 in)
Exhaust
Standard: 1.2 mm (0.0472 in)
Limit: 1.1 mm (0.0433 in)
Contact surface angle on valve seat on
valve
1. Measure contact surface angle on valve seat.
2. If the measured value exceeds the limit, replace
valve, valve guide and valve seat as a set.
Standard: 68°
011RW001
012RW052
012RW060
014RW018

6A – 64 ENGINE MECHANICAL
Valve Depression
1. Measure the valve stem height from the upper
surface of the cylinder head as shown in the
illustration.
Standard:
Intake side 35.59 mm (1.4012 in)
Exhaust side 35.49 mm (1.3972 in)
Limit:
Intake side 35.74 mm (1.4071 in)
Exhaust side 35.64 mm (1.4031 in)
Legend
(1) Intake Side
(2) Exhaust Side
Valve Contact Width
1. Check the valve contact faces for roughness and
unevenness. Make the valve contact surfaces
smooth.
2. Measure the valve contact width.
If the measured value exceeds the specified limit,
the valve seat insert must be replaced.
Inlet
Standard: 2.1 mm (0.0827 in)
Limit: 2.6 mm (0.1024 in)
Exhaust
Standard: 2.0 mm (0.0787 in)
Limit: 2.5 mm (0.0984 in)
Valve Seat Insert Replacement
Valve Seat Insert Removal
1. Arc weld the entire inside circumference of the
valve seat insert.
2. Allow the valve seat insert to cool for a few minutes.
This will invite contraction and make removal of the
valve seat insert easier.
3. Use a screwdriver to pry the valve seat insert free.
Take care not to damage the cylinder head.
4. Carefully remove carbon and other foreign material
from the cylinder head insert bore.

011RW044
014RS015

ENGINE MECHANICAL 6A – 65
Valve Seat Insert Installation
1. Carefully place the attachment (1) (having a smaller
outside diameter than the valve seat insert) on the
valve seat insert (2).
Legend
(1) Attachment
(2) Valve Seat Insert
(3) Bench Press
NOTE: The smooth side of the attachment must contact
the valve seat insert.
2. Use a bench press (3) to gradually apply pressure
to the attachment and press the valve seat insert
into place.
Note: Do not apply an excessive amount of pressure
with the bench press. Damage to the valve seat insert
will result.
Valve Seat Insert Correction
1. Remove the carbon from the valve seat insert
surface.
2. Use a valve cutter (15°, 45°and 75°blades) to
minimize scratches and other rough areas. This will
bring the contact width back to the standard value.
Remove only the scratches and rough areas. Do
not cut away too much. Take care not to cut away
unblemished areas of the valve seat surface.
Valve Seat Angle: 45°NOTE: Use an adjustable valve cutter pilot.
Do not allow the valve cutter pilot to wobble inside the
valve guide.
3. Apply abrasive compound to the valve seat insert
surface.
4. Insert the valve into the valve guide.
5. Turn the valve while tapping it to fit the valve seat
insert.
6. Check that the valve contract width is correct.
7. Check that the valve seat insert surface is in
contact with the entire circumference of the valve.
3
2 1
012RW055
150°
90°
30°
012RW056
014RS014

6A – 66 ENGINE MECHANICAL
INSTALLATION
1. Valve stem seal
1) Use the special tool to install the stem seal to the
valve guide.
Stem Seal Installer: 5-8840-2033-0
2. Valve spring.
1) Install the lower valve seat spring, valve spring,
then the upper valve spring seat.
2) Use valve spring compressor to compress the
spring then install the split collar.
Valve spring compressor: 5-8840-2441-0
NOTE: Make sure the split collar installs completely.
3. Install cylinder head assembly.
Refer to “Cylinder Head” in this manual.
4. Install the camshaft carrier with camshaft.
Refer to “Camshaft” in this manual.
5. Install oil rail assembly.
Refer to “Oil rail and injector” in this manual.
6. Install injector assembly.
Refer to “Oil rail and injector” in this manual.
7. Install the injector harness assembly.
Refer to “Injector” in this manual.
8. Reconnect harness connecter to oil pressure
sensor and oil temperature sensor on the oil rail.
9. Reconnect Injector harness connecter to injector.
Refer to “Injector” in this manual.
10. Install cylinder head cover with gasket.
Refer to “Cylinder Head Cover” in this manual.
11. Install glow plug with specified torque.
Torque: 15 N·m (1.5 kg·m / 10.8 lb ft)
12. Install the intake manifold assembly.
Refer to “Intake Manifold” in this manual.
13. Install the fuel pipe.14. Install the water pipe between the cylinder head
and water pump.
Torque: 20 N·m (2.0 k·m / 14.5 lb ft)
15. Install the front plate.
16. Install the camshaft pulley.
Refer to “Timing Gear” in this manual.
17. Install timing belt and set the tensioner.
Refer to “Timing Belt” in this manual.
18. Install CMP sensor bracket.
Torque: 20 N·m (2.0 kg·m / 14.5 lb ft)
19. Install timing belt cover.
Torque: 9 N·m (0.9 kg·m / 6.5 lb ft)
20. Fill the oil rail with engine oil then immediately
install the high pressure oil pipe with the specified
torque.
Torque: 80 N·m (8.1 kg·m / 57.9 lb ft)
21. Install the noise insulator cover.
22. Reconnect hose between thermostat and radiator.
23. Install turbocharger assembly.
Refer to “Turbocharger” in this manual.
24. Install water hose and oil pipe for turbocharger.
Refer to “Turbocharger” in this manual.
25. Install the valve assembly and install heat protector.
26. Install generator and set the fan belts.
27. Install A/C compressor bracket, compressor
assembly and set drive belt.
28. Reconnect harness connector around cylinder
head.
29. Reconnect vacuum hose to EGR valve.
30. Reconnect PCV hose.
31. Install oil level gauge guide assembly.
32. Install intercooler assembly.
Refer to “Intercooler” in this manual.
33. Install the air duct assembly.
34. Fill engine coolant.
35. Connect battery ground cable.
014RW042

ENGINE MECHANICAL 6A – 67
VALVE CLEARANCE ADJUSTMENT
NOTE:
1. Valve clearance should be inspected and adjusted
while the engine is cool.
2. The tightening of the camshaft bearing cap and
camshaft carrier assembly should be checked
before inspecting and adjusting valve clearance.
INSPECTION
1. Remove cylinder head noise insulator cover and
cylinder head cover.
Refer to “Cylinder Head” in this manual.
2. Disconnect all harness connecters of the injector
and remove harness assembly.
3. Drain oil from oil rail assembly.
4. Remove injector clamp nuts and fixing bolts to take
out injector assembly.
5. Loosen oil rail bolts, remove oil rail assembly.
6. Set cylinder No.1 to the TDC at the compression
stroke. Make sure that there is play in cylinder No.1
tappets on inlet and exhaust sides and that there is
no play in cylinder No.4 tappets.
7. Measure valve clearance at No.1 TDC (Refer to the
black circles indicated in the illustration).
Standard Valve clearance:
Intake valve: 0.15 mm (0.0059 in) ± 0.05 mm (0.0020 in)
Exhaust valve: 0.25 mm (0.0098 in) ± 0.05 mm (0.0020 in)
8. Turn the crankshaft one turn to set No.4 cylinder
TDC at the compression stroke.
9. Measure valve clearance at No.4 TDC (Refer to the
black circles indicated in the illustration).
Standard Valve clearance:
Intake valve: 0.15 mm (0.0059 in) ± 0.05 mm (0.0020 in)
Exhaust valve: 0.25 mm (0.0098 in) ± 0.05 mm (0.0020 in)
10. If measured value is outside standard value,
readjust the valve clearance.
ADJUSTMENT
For valve clearance adjustment, follow the procedure
given below.
1. Set cylinder No.1 or No.4 to the TDC at the
compression stroke.
Set the valve clearance adjusting tool on the tappet
requiring adjustment.
After making sure of the correct setting of the
special tool, depress the tappet by turning the bolt.
Valve Clearance Adjusting Tool: 5-8840-2590-0
NOTE: Before depressing the tappet, set the tappet
notch in the direction where adjuster can be easily
taken out.
2. Take out the adjuster using a small screw driver and
finger magnet.
No.1
FtNo.2No.1 TDC
No.3 No.4EXH
IN
011RW045
No.1
FtNo.2No.4 TDC
No.3 No.4EXH
IN
011RW046
014RW150