engine coolant ISUZU TROOPER 1998 Service Owner's Manual

6A±11
ENGINE MECHANICAL
Condition CorrectionPossible cause
Engine overheatingLevel of Engine Coolant too lowReplenish
Fan clutch defectiveReplace
Incorrect fan installedReplace
Thermostat defectiveReplace
Engine Coolant pump defectiveCorrect or replace
Radiator cloggedClean or replace
Radiator filler cap defectiveReplace
Level of oil in engine crankcase too
low or wrong engine oilChange or replenish
Resistance in exhaust system
increasedClean exhaust system or replace
defective parts
Throttle Position Sensor adjustment
incorrectReplace with Throttle Valve ASM
Throttle Position Sensor circuit open
or shortedCorrect or replace
Cylinder head gasket damagedReplace
Engine overcoolingThermostat defectiveReplace (Use a thermostat set to
open at 82
C (180
F))
Engine lacks compressionÐÐÐÐRefer to Hard Start
OthersTire inflation pressure abnormalAdjust to recommended pressures
Brake dragAdjust
Clutch slippingAdjust or replace
Level of oil in engine crankcase too
highCorrect level of engine oil
Exhaust Gas Recirculation Valve
defectiveReplace
Engine Noisy
Abnormal engine noise often consists of various noises
originating in rotating parts, sliding parts and othermoving parts of the engine. It is, therefore, advisable to
locate the source of noise systematically.
Condition
Possible causeCorrection
Noise from crank journals or from
crank bearings
(Faulty crank journals and crankOil clearance increased due to worn
crank journals or crank bearingsReplace crank bearings and
crankshaft or regrind crankshaft and
install the undersize bearing
yj
bearings usually make dull noise that
becomes more evident when
accelerating)Crankshaft out of roundReplace crank bearings and
crankshaft or regrind crankshaft and
install the undersize bearing
Crank bearing seizedCrank bearing seized. Replace crank
bearings and crankshaft or regrind
crankshaft and install the undersize
bearing
Troubleshooting Procedure
Short out each spark plug in sequence using insulated
spark plug wire removers. Locate cylinder with defectivebearing by listening for abnormal noise that stops when
spark plug is shorted out.

6A±13
ENGINE MECHANICAL
Condition CorrectionPossible cause
Engine knockingPreignition due to use of spark plugs
of inadequate heat rangeInstall Spark Plugs of adequate heat
range
Carbon deposits in combustion
chambersClean
Fuel too low in octane ratingReplace fuel
Wide Open Throttle enrichment
system failureRefer to Section 6E
Selection of transmission gear
incorrectCaution operator of incorrect gear
selection
Engine overheatingRefer to ªEngine Lacks Powerº
OthersWater pump defectiveReplace
Drive belt slippingReplace auto tentioner or drive belt
Abnormal Combustion
ConditionPossible causeCorrection
Trouble in fuel systemFuel pressure control valve defectiveReplace
Fuel filter cloggedReplace
Fuel pump cloggedClean or replace
Fuel tank or fuel pipe cloggedClean or replace
Fuel injector cloggedClean or replace
Fuel pump relay defectiveReplace
Power supply cable for fuel pump
broken or poor connectionsReconnect, correct or replace
Mass Airflow (MAF) sensor circuit
open or defectiveCorrect or replace
MAF Sensor defectiveReplace
Manifold Absolute Pressure Sensor
circuit open or shortedCorrect or replace
Manifold Absolute Pressure Sensor
defectiveReplace
Engine Coolant Temperature (ECT)
Sensor circuit open or shortedCorrect or replace
ECT Sensor defectiveReplace
Throttle Position Sensor adjustment
incorrectReadjust
Throttle Position Sensor defectiveReplace
Throttle Position Sensor connector
poor connectionsReconnect
Vehicle Speed Sensor cable poor
connections or defectiveCorrect or replace
Vehicle Speed Sensor loosely fixedFix tightly
Vehicle Speed Sensor in wrong
contact or defectiveReplace
Powertrain Control Module cable
poor connections or defectiveCorrect or replace

6A±17
ENGINE MECHANICAL
Malfunction Indicator Lamp
The instrument panel ªCHECK ENGINEº Malfunction
Indicator Lamp (MIL) illuminates by self diagnosticsystem when the system checks the starting of engine, or
senses malfunctions.
Condition
Possible causeCorrection
ªCHECK ENGINEº MIL does not
illuminate at the starting of engine
Bulb defectiveReplace
illuminate at the starting of engineMIL circuit openCorrect or replace
Command signal circuit to operate
self diagnostic system shortedCorrect or replace
Engine Control Module (PCM) cable
loosely connected, disconnected or
defectiveCorrect or replace
PCM defectiveReplace
ªCHECK ENGINEº MIL illuminates,
and stays onDeterioration of heated oxygen
sensor internal elementReplace
Heated oxygen sensor connector
terminal improper contactReconnect properly
Heated oxygen sensor lead wire
shortedCorrect
Heated oxygen sensor circuit openCorrect or replace
Deterioration of engine coolant
temperature sensor internal elementReplace
Engine coolant temperature sensor
connector terminal improper contactReconnect properly
Engine coolant temperature sensor
lead wire shortedCorrect
Engine coolant temperature sensor
circuit openCorrect or replace
Throttle position sensor open or
shorted circuitsCorrect or replace
Deterioration of crankshaft position
sensorReplace
Crankshaft position sensor circuit
open or shortedCorrect or replace
Vehicle speed sensor circuit openCorrect or replace
Manifold absolute pressure sensor
circuit open or shortedCorrect or replace
Intake air temperature sensor circuit
open or shortedCorrect or replace
Fuel injector circuit open or shortedCorrect or replace
PCM driver transistor defectiveReplace PCM
Malfunctioning of PCM RAM
(Random Access Memory) or ROM
(Read Only Memory)Replace PCM

6A±18
ENGINE MECHANICAL
Cylinder Head Cover LH
Removal
1. Disconnect battery ground cable.
2. Drain engine coolant from faucet bottom of radiator.
3. Remove engine cover from the dowels on the
common chamber.
F06RW018
4. Remove air cleaner duct assembly (3) and air cleaner
element (4).
130RW001
Legend
(1) Positive Crankcase Ventilation Hose Connector
(2) Intake Air Temperature Sensor
(3) Air Cleaner Duct Assembly
(4) Air Cleaner Element
(5) Mass Air Flow Sensor
NOTE: Disconnect the mass air flow (MAF) sensor
connector, intake air temperature (IAT) sensor connector,
and positive crankcase ventilation (PCV) hose before
hand the air cleaner duct assembly is removed.5. Disconnect following wiring connectors and bonding
cable:

Manifold Absolute Pressure (MAP) sensor

Vacuum Switching Valve (VSV) for Induction Air
Control Valve (IACV) actuator

Ignition coils for left bank

Fuel injectors for left bank

Idle air control (IAC) valve

Throttle position sensor (TPS)

Bonding cable

Others as necessitated
6. Disconnect following vacuum hoses:

Brake master VAC

Canister

VSV for IACV actuator

Duty solenoid valve

PCV
7. Disconnect radiator upper and lower hoses
8. Remove engine harness from the cylinder head
cover.
9. Remove the upper fan guide.
10. Remove cooling fan and clutch assembly.
11. Remove drive belt by pushing down the auto
tensioner using spanner as illustrated.
F06RW019

6A±21
ENGINE MECHANICAL
Cylinder Head Cover RH
Removal
1. Disconnect battery ground cable.
2. Remove battery from the vehicle.
3. Drain engine coolant from faucet bottom of radiator.
4. Remove engine cover from the dowels on the
common chamber.
F06RW018
5. Remove air cleaner duct assembly (3) and air cleaner
element (4).
130RW001
Legend
(1) Positive Crankcase Ventilation Hose Connector
(2) Intake Air Temperature Sensor
(3) Air Cleaner Duct Assembly
(4) Air Cleaner Element
(5) Mass Air Flow Sensor
NOTE: Disconnect the mass air flow (MAF) sensor
connector, intake air temperature (IAT) sensor connector,
and positive crankcase ventilation (PCV) hose before
hand the air cleaner duct assembly is removed.
6. Disconnect following wiring connectors and bonding
cable:

Exhaust Gas Recirculation (EGR) valve

Fuel injectors for right bank

Ignition coils for right bank

Bonding cable

Othres as necessitated
7. Disconnect radiator upper and lower hoses.
8. Remove engine harness from the cylinder head
cover.
9. Remove the upper fan guide.
10. Remove cooling fan and clutch assembly.
11. Remove drive belt by pushing down the auto
tensioner using spanner as illustrated.
F06RW019
Legend
(1) Crankshaft Pulley
(2) Generator
(3) Auto Tensioner
(4) Idle Pulley
(5) Cooling Fan Pulley
(6) Power Steering Oil Pump
(7) Drive Belt
(8) Air Conditioner Compressor
12. Remove fan pulley and bracket assembly.
13. Remove idle pulley assembly.
14. Remove auto tensioner assembly.
15. Remove crankshaft pulley using 5±8840±0133±0
crankshaft holder.

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 ªRº for right bank
and ªLº 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.
Torque :
Temporary : 29 N´m (3.0 Kg´m/21 lb ft)
Final : 64 N´m (6.5 Kg´m/47 lb ft)
014RW029

6A±39
ENGINE MECHANICAL
Valve Stem Oil Controller , Valve Spring and Valve Guide
Removal
1. Disconnect battery ground cable.
2. Drain engine oil.

Drain engine coolant.
3. Remove cylinder head assembly.

Refer to removal procedure for Cylinder Head in
this manual.
4. Remove camshaft.

Refer to removal procedure for Camshaft in this
manual.
5. Remove tappets with shim.
NOTE: Do not damage shim surface.
6. Remove valve springs using 5±8840±2446±0 valve
spring compressor and 5±8840±2547±0 valve spring
compressor adapter then remove upper valve spring
seat and lower seat.
014RW042
7. Remove oil controller using 5±8840±0623±0 oil
controller remover, remove each valve stem oil
controller.
8. Remove valve guide using 5±8840±2549±0 valve
guide replacer.
Installation
1. Install valve guide using 5±8840±2442±0 valve guide
installer.
2. Install oil controller using 5±8840±0624±0 oil
controller installer.
3. Install lower valve spring seat, valve spring and upper
valve spring seat then put split collars on the upper
spring seat, using 5±8840±2446±0 valve spring
compressor and 5±8840±2547±0 valve spring
compressor adapter to install the split collars.
014RW042
4. Install tappet with shim.
5. Install camshaft assembly.

Refer to installation procedure for Camshaft in this
manual.
6. Install cylinder head assembly.

Refer to installation procedure for Cylinder Head in
this manual.
7. Fill engine oil until full level.
8. Fill engine coolant.

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 assembling the engine and
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 N´m (2.2 Kg´m/16 lb ft)
M10 bolts : 43 N´m (4.4 Kg´m/32 lb ft)
10. Install power steering pump, tighten fixing bolt to the
specified torque.
Torque :
M8 bolts : 22N´m (2.2 Kg´m/16 lb ft)
M10 bolts : 46 N´m (4.7 Kg´m/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
sure that the valve lever returns up to the stopper
screw.

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