6A–37
ENGINE MECHANICAL
Cylinder Head
Removal
1. Remove engine hood.
2. Disconnect battery ground cable.
3. Drain radiator coolant.
4. Drain engine oil.
5. Remove crankshaft pulley.
Refer to removal procedure for Crankshaft Pulley in
this manual.
6. Remove timing belt.
Refer to removal procedure for Timing Belt in this
manual.
7. Remove cylinder head cover LH.
Refer to removal procedure for Cylinder Head
Cover LH in this manual.
8. Remove cylinder head cover RH.
Refer to removal procedure for Cylinder Head
Cover RH in this manual.
9. Remove common chamber.
Refer to removal procedure for Common Chamber
in this manual.
10. Remove cylinder head assembly.
1. Loosen eights bolts for tight cylinder head.
2. Remove cylinder head assembly.
014RW028
Legend
(1) Cylinder Head
(2) Cylinder Head Bolt
(3) Camshaft
Installation
1. Install cylinder head assembly to cylinder block.
1. Put cylinder head gasket on the cylinder block.NOTE: There is discrimination mark “R” for right bank
and “L” for left bank on the cylinder head gasket as shown
in the illustration.
Do not reuse cylinder head gasket.
011RW005
2. Align dowel pin hole to dowel pin on the cylinder
block.
3. Tighten two bolts temporarily by hand to prevent
the cylinder head assembly from moving.
4. Using 9–8511–4209–0 cylinder head bolt wrench,
tighten bolts in numerical order as shown in the
illustration to the specified torque.
NOTE: Do not reuse cylinder head bolts.
Do not apply any lubricant to the cylinder head bolts.
To r q u e :
Temporary : 29 Nꞏm (3.0 Kgꞏm/21 lb ft)
Final : 64 Nꞏm (6.5 Kgꞏm/47 lb ft)
014RW029
6A–48
ENGINE MECHANICAL
Engine Assembly
Removal
035RW027
1. Disconnect battery ground and positive cable.
2. Remove battery.
3. Make alignment mark on the engine hood and hinges
before removal in order to return the hood to original
position exactly.
4. Remove engine hood.
5. Drain radiator coolant.
6. Disconnect accelerator cable and automatic cruise
control cable from throttle valve on common
chamber.
7. Disconnect air duct with air cleaner cover.
8. Remove air cleaner assembly.
9. Disconnect canister vacuum hose.
10. Disconnect vacuum booster hose.
11. Disconnect three engine harness connectors.
12. Disconnect harness connector to transmission (left
front side of engine compartment), disconnect shift
on the fly harness connector from front side of front
axle and remove transmission harness bracket from
engine left side.
13. Disconnect ground cable between engine and frame.
14. Disconnect bonding cable connector on the back of
right dash panel.
15. Disconnect bonding cable terminal on the left bank.
16. Disconnect starter harness connector from starter.
17. Disconnect generator harness connector from
generator.
18. Disconnect coolant reserve tank hose from radiator.
19. Remove radiator upper and lower hoses.
20. Remove upper fan shroud.
21. Remove cooling fan assembly four fixing nuts, then
the cooling fan assembly.
22. Move drive belt tensioner to loose side using wrench
then remove drive belt.23. Remove power steering pump fixing bolts, then
power steering pump. Place the power steering pump
along with piping on the body side.
24. Remove air conditioning compressor fixing bolts from
bracket and place the compressor along with piping
on the body side.
25. Remove O
2 sensor harness connectors from exhaust
front pipe.
26. Remove three exhaust pipe fixing nuts from each
bank.
27. Remove two exhaust pipe fixing nuts from each
exhaust pipe, then move exhaust pipe to rear side of
vehicle.
28. Remove flywheel dust covers.
29. Disconnect two heater hoses from engine.
30. Disconnect fuel hoses from right side of transmission.
CAUTION: Plug fuel pipes on engine side and fuel
hoses from fuel tank.
31. Remove transmission assembly. Refer to
Transmission section in this manual.
32. Support the engine by engine hoist.
33. Remove two left side engine mount fixing bolts from
engine mount on chassis side.
34. Remove two right side engine mount fixing bolts from
engine mount on chassis side.
35. Remove engine assembly.
Installation
CAUTION: W h e n a s s e m b l i n g t h e e n g i n e a n d
transmission, confirm that dowels have been
mounted in the specified positions at the engine
side. Take care that dowel positions are different
between the manual transmission and the automatic
transmission.
6A–50
ENGINE MECHANICAL
9. Install air conditioner compressor to engine and
tighten to the specified torque.
Torque :
M8 bolts : 22 Nꞏm (2.2 Kgꞏm/16 lb ft)
M10 bolts : 43 Nꞏm (4.4 Kgꞏm/32 lb ft)
10. Install power steering pump, tighten fixing bolt to the
specified torque.
Torque :
M8 bolts : 22Nꞏm (2.2 Kgꞏm/16 lb ft)
M10 bolts : 46 Nꞏm (4.7 Kgꞏm/34 lb ft)
11. Move drive belt tensioner to loose side using wrench,
then install drive belt to normal position.
850RW001
Legend
(1) Crankshaft Pulley
(2) Cooling Fan Pulley
(3) Tensioner
(4) Generator
(5) Air Conditioner Compressor
(6) Power Steering Oil Pump
(7) Drive Belt
12. Install upper fan shroud.
13. Reconnect radiator upper and lower hoses.
14. Reconnect coolant reserve tank hose to radiator.
15. Reconnect generator harness connector.
16. Reconnect starter harness connector.
17. Reconnect bonding cable terminal on left bank
18. Reconnect bonding cable terminal on the back of right
dash panel.19. Reconnect ground cable between engine and
chassis.
20. Reconnect harness connector to transmission and
install transmission harness bracket on engine left
side.
21. Reconnect three engine harness connectors.
22. Reconnect vacuum booster hose.
23. Reconnect canister vacuum hose.
24. Install air cleaner assembly.
25. Reconnect air duct.
26. Reconnect accelerator cable and automatic cruise
control cable to throttle valve on common chamber.
035RW007
Legend
(1) Throttle Valve Assembly
(2) Throttle Lever
(3) Idle Air Control Valve
(4) Throttle Position Sensor
27. Install engine hood to the original position.
Refer to installation procedure for Body section in
this manual.
Accelerator pedal cable adjustment
1. Loosen adjusting nut and lock nut.
2. Pull outer cable while fully closing the throttle
valve.
3. Tighten adjusting nut and lock nut temporarily.
4. Loosen adjusting nut by three turns and tighten
lock nut.
Then, manually operating the throttle valve, make
s u r e t h a t t h e v a l v e l e v e r r e t u r n s u p t o t h e s t o p p e r
screw.
ENGINE COOLING6B–1
ENGINE
ENGINE COOLING
CONTENTS
Service Precaution 6B–1. . . . . . . . . . . . . . . . . . . . . .
General Description 6B–2. . . . . . . . . . . . . . . . . . . . .
Diagnosis 6B–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Draining and Refilling Cooling System 6B–6. . . . .
Water Pump 6B–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Pump and Associated Parts 6B–7. . . . . . .
Removal 6B–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 6B–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6B–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat 6B–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat and Associated Parts 6B–8. . . . . . . .
Removal 6B–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 6B–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . Installation 6B–8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radiator 6B–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radiator and Associated Parts 6B–9. . . . . . . . . .
Removal 6B–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 6B–10. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6B–11. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drive Belt and Cooling Fan 6B–12. . . . . . . . . . . . . . .
Drive Belt and Associated Parts 6B–12. . . . . . . . .
Inspection 6B–12. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6B–12. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 6B–13. . . . . . . . . . . . .
Special Tool 6B–14. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Precaution
WARNING: IF SO EQUIPPED WITH A
SUPPLEMENTAL RESTRAINT SYSTEM (SRS),
REFER TO THE SRS COMPONENT AND WIRING
LOCATION VIEW IN ORDER TO DETERMINE
WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS
WIRING. WHEN YOU ARE PERFORMING SERVICE
ON OR NEAR THE SRS COMPONENTS OR THE SRS
WIRING, REFER TO THE SRS SERVICE
INFORMATION. FAILURE TO FOLLOW WARNINGS
COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.
6B–2
ENGINE COOLING
General Description
030RW001
Legend
(1) Water Pump
(2) Thermostat
(3) Radiator
(4) Reserve Tank
(5) Cooling Fan
(6) Cylinder Block(7) Cylinder Head
(8) Right Bank
(9) Throttle Body
(10) Cylinder Block
(11) Cylinder Head
(12) Left Bank
(13) Heater
The cooling system is a pressurized Engine Coolant (EC)
forced circulation type which consists of a water pump,
thermostat cooling fan, radiator and other components.
The automatic transmission fluid is cooled by the EC in
radiator.
Water Pump
The EC pump is a centrifugal impeller type and is driven
by a timing belt.
030RS001
ENGINE COOLING6B–3
Thermostat
The thermostat is a wax pellet type with a air hole(1) and is
installed in the thermostat housing.
031RW002
Radiator
The radiator is a tube type with corrugated fins. In order to
raise the boiling point of the coolant, the radiator is fitted
with a cap in which the valve is operated at 88.2
117.6
kPa (12.8
1 7 . 0 p s i ) p r e s s u r e . ( N o o i l c o o l e r p r o v i d e d f o r
M/T)
110RS001
Anti Freeze Solution
Relation between the mixing ratio and freezing
temperature of the EC varies with the ratio of
anti–freeze solution in water. Proper mixing ratio can
be determined by referring to the chart. Supplemental
inhibitors or additives claiming to increase cooling
capability that have not been specifically approved by
Isuzu are not recommended for addition to the cooling
system.
Calculating mixing ratio
F06RW005
ENGINE COOLING6B–5
Diagnosis
Engine Cooling Trouble
ConditionPossible causeCorrection
Engine overheatingLow Engine Coolant levelReplenish
Incorrect fan installedReplace
Thermo meter unit faultyReplace
Faulty thermostatReplace
Faulty Engine Coolant temperature
sensorRepair or replace
Clogged radiatorClean or replace
Faulty radiator capReplace
Low engine oil level or use of
improper engine oilReplenish or change oil
Clogged exhaust systemClean exhaust system or replace
faulty parts
Faulty Throttle Position sensorReplace throttle valve assembly
Open or shorted Throttle Position
sensor circuitRepair or replace
Damaged cylinder head gasketReplace
Engine overcoolingFaulty thermostatReplace
Engine slow to warm–upFaulty thermostatReplace
Thermo unit faultyReplace
6B–6
ENGINE COOLING
Draining and Refilling Cooling
System
Before draining the cooling system, inspect the system
and perform any necessary service to ensure that it is
clean, does not leak and is in proper working order. The
engine coolant (EC) level should be between the “MIN”
and “MAX” lines of reserve tank when the engine is cold.
If low, check for leakage and add EC up to the “MAX” line.
There should not be any excessive deposit of rust or
scales around the radiator cap or radiator filler hole, and
the EC should also be free from oil.
Replace the EC if excessively dirty.
1. Completely drain the cooling system by opening the
drain plug (2) at the bottom of the radiator.
110RW002
2. Remove the radiator cap.
WARNING: TO AVOID THE DANGER OF BEING
BURNED, DO NOT REMOVE THE CAP WHILE THE
ENGINE AND RADIATOR ARE STILL HOT.
SCALDING FLUID AND STEAM CAN BE BLOWN OUT
UNDER PRESSURE.
3. Disconnect all hoses from the EC reserve tank.
Scrub and clean the inside of the reserve tank with
soap and water. Flush it well with clean water, then
drain it. Install the reserve tank and hoses.
4. Refill the cooling system with the EC using a solution
that is at least 50 percent antifreeze but no more than
70 percent antifreeze.
5. Fill the radiator to the base of the filler neck.
Fill the EC reserve tank to “MAX” line when the engine
is cold.
6. Block the drive wheels and firmly apply the parking
brake. Shift an automatic transmission to “P” (Park)
or a manual transmission to neutral.
7. Remove the radiator cap. Start the engine and warm
it up at 2,500
3,000 rpm for about 30 minutes.
8. When the air comes out from the radiator filler neck
and the EC level has gone down, replenish with the
EC. Repeat this procedure until the EC level does not
go down. Then stop the engine and install the radiator
cap. Let the engine cool down.9. After the engine has cooled, replenish with EC up to
the “MAX” line of the reserve tank.
10. Start the engine. With the engine running at 3,000
rpm, make sure there is no running water sound from
the heater core (behind the center console).
11. If the running water sound is heard, repeat steps 8 to
10.