1998 ISUZU TROOPER check engine

ENGINE MECHANICAL 6A – 19
Injector
N·m (kg·m/lb·ft)
E06R200022
With
spacer type
Without
spacer type
20N·m(2.0kg·m/14 Ib ft)
7N·m(0.7kg·m/61 Ib in)
Recheck tightening torque
after tighten the oil rail
Apply engine oil on the
thread of stud bolts
20N·m(2.0kg·m/14 Ib ft)
Tighten 30N·m(3.1kg·m/22 Ib ft)
Then loosen it again tighten with
24N·m(2.4kg·m/17 Ib ft)
Apply engine oil
both side

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

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

ENGINE MECHANICAL 6A – 75
DISASSEMBLY
1. Cylinder Head
1) Refer to “Cylinder head” in this manual.
2. Crankshaft Front Oil Seal
1) Use a plastic hammer and a screwdriver to tap
around the oil seal to free it from the gear case
cover.
Take care not to damage the oil seal fitting
surfaces.
3. Crankshaft Timing Gear
4. Timing Gear Case
5. Flywheel
6. Cylinder Block Rear Plate
7. Crankshaft Rear Oil Seal
1) Use special tool to remove the crankshaft rear
oil seal.
Oil Seal Remover: 5-8840-2360-0
8. Crank Case
9. Piston Cooling Oil Pipe
10. Piston and Connecting Rod Assembly
11. Main Bearing Cap Assembly
12. Crankshaft
INSPECTION AND REPAIR
Make the necessary adjustments, repairs, and part
replacements if excessive wear or damage is
discovered during inspection.
1. Crankshaft Thrust clearance
Set the dial indicator as shown in the illustration and
measure the crankshaft thrust clearance.
If the thrust clearance exceeds the specified limit,
replace the thrust bearing as a set.
Standard : 0.04 – 0.20 mm (0.0016 – 0.0079 in)
Limit: 0.30 mm (0.0118 in)2. Main bearing clearance
1) Remove the main bearing caps in the sequence
shown in the illustration.
Arrange the removed main bearing caps in the
cylinder number order.
2) Remove the crankshaft. Remove the main
bearings.
3) Clean the upper and lower bearings as well as
the crankshaft main journal.
4) Check the bearings for damage or excessive
wear.
The bearings must be replaced as a set if
damage or excessive wear is discovered during
inspection.
5) Set the upper bearings and the thrust washers
to their original positions. Carefully install the
crankshaft.
6) Set the lower bearings to the bearing cap
original position.
015LV002
012RW063
371062
51
98
4
012RW026

ENGINE MECHANICAL 6A– 79
Main Bearing Crankshaft
Bore Diameter mm(in) Main Journal Diameter mm(in)Crankshaft Oil Clearance
Grade Inside Diameter Grade Outside DiameterBearing mm(in)
1 or - 69.927 – 69.932 4 0.045 – 0.061
(2.7530 – 2.7532) (0.0018 – 0.0024)
1 73.992 – 74.000 2 or - - 69.922 – 69.927 4 0.050 – 0.066
(2.9131 – 2.9134) (2.7528 – 2.7530) (0.0020 – 0.0026)
3 or - - - 69.917 – 69.922 5 0.052 – 0.068
(2.7526 – 2.7528) (0.0020 – 0.0027)
1 or - 69.927 – 69.932 2 0.042 – 0.059
(2.7530 – 2.7532) (0.0017 – 0.0023)
2 73.983 – 73.992 2 or - - 69.922 – 69.927 3 0.044 – 0.061
(2.9127 – 2.9131) (2.7528 – 2.7530) (0.0017 – 0.0024)
3 or - - - 69.917 – 69.922 4 0.046 – 0.063
(2.7526 – 2.7528) (0.0018 – 0.0025)
1 or - 69.927 – 69.932 1 0.037 – 0.053
(2.7530 – 2.7532) (0.0015 – 0.0021)
3 73.975 – 73.983 2 or - - 69.922 – 69.927 2 0.039 – 0.055
(2.9124 – 2.9127) (2.7528 – 2.7530) (0.0015 – 0.0022)
3 or - - - 69.917 – 69.922 2 0.044 – 0.060
(2.7526 – 2.7528) (0.0017 – 0.0024)
REASSEMBLY
1. Crankshaft
1) Install the main bearings to the cylinder body
and the main bearing caps.
2) Be sure that they are positioned correctly.
3) Apply new engine oil to the upper and lower
main bearing faces.
4) Carefully mount the crankshaft.
5) Apply engine oil to the thrust washer.
6) Assemble the thrust washer to the No. 3 bearing
journal. The oil grooves must face the
crankshaft.7) Install the bearing caps with the bearing cap
head arrow mark facing the front of the engine.
8) Apply engine oil to the crankshaft bearing cap
bolts.
9) Tighten the crankshaft bearing cap bolts to the
specified torque a little at a time in the sequence
shown in the illustration.
Torque: 167 N·m (17.0 kg·m/123 lb ft)
NOTE: Check to see that the crankshaft turns smoothly
by rotating it manually.
012RW047
84159
610
23
7
012RW027

6A– 80 ENGINE MECHANICAL
3. Piston and Connecting Rod Assembly
1) Apply engine oil to the cylinder bores, the
connecting rod bearings and the crankshaft pins
and each piston ring and piston.
2) Align the front mark (2) of piston and front mark
(3) of connecting rod then assemble them.
3) The N mark of the piston ring is faced toward the
top, check to see that the piston ring end gap is
correctly positioned.
Legend
(1) 1st piston ring end gap
(2) 2nd piston ring end gap
(3) Oil ring end gap4) Insert the piston/connecting rod assemblies into
each cylinder with the piston ring compressor.
The front marks must be facing the front of the
engine.
Piston Ring Compressor: 5-8840-9018-0
5) Match the numbered caps with the numbers on
the connecting rods. Align the punched marks
on the connecting rods and caps.
6) Apply engine oil to the threads and seating faces
of the nuts.
7) Tighten the cap nuts in 2 steps, using angular
tightening method as shown in the following
specifications.
1st step: 29 N·m (3.0 kg·m/22 lb ft)
2nd step: 45°– 60°
After tightening the cap nuts, check to see that
the crankshaft rotates smoothly
4. Piston Cooling Oil Pipe
If the piston cooling oil pipe is forcibly assembled,
the end of the oil jet may bend. It could make it
impossible to supply oil to the piston cooling holes,
which will sometimes cause piston seizure.
Sufficient care should be taken to pipe assembly
work.
1) Tighten the bolt and oil jet plug to the specified
torque.
Torque:
M6: 8 N·m (0.8 kg·m/6 lb ft)
M8: 20 N·m (2.0 kg·m/14.5 lb ft)
Oiling Jet Plug: 30 N·m (3.1 kg·m/22 lb ft)
5. Crank case
1) Refer to “Crank case” in this manual.
6. Apply liquid gasket (TB-1207C or equivalent) to
retainer then install it to rear end of cylinder block
within 5 minutes.
7. Crankshaft Rear Oil Seal
1) Tighten the adapter to the crankshaft rear and
section with 2 bolts.
2) Insert the oil seal into the peripheral section of
the adapter.
3) Insert the sleeve into the adapter and tighten it
with a bolt (M12 x 1.75L = 70) until the adapter
hits the sleeve.
4) Remove the adapter and the sleeve.
5) Check the dimension of the oil seal setting from
rear end of crankshaft.
Standard Dimension = 12.5 ± 0.3 mm
Oil Seal Installer: 5-8840-2359-0
2
3
1
015RW051
3
1
2
015RW083