1998 ISUZU TROOPER coolant level

6A – 46 ENGINE MECHANICAL
Legend
(1) Cylinder Head Noise Insulator Cover
(2) Insulator
(3) Bolt
(4) Oil Seal
(5) Gasket
(6) Cylinder Head Cover
(7) Bolt, Stud and Rubber Mounting
21. Install water hose between thermostat and radiator.
22. Install turbocharger assembly to exhaust manifold.
Torque: 27 N·m (2.8 kg·m/20.2 lb ft)
23. Install water hose and oil pipe for turbocharger.
24. Install exhaust valve assembly and heat protector.
Torque: 27 N·m (2.8 kg·m/20.2 lb ft) for valve
Torque: 9 N·m (0.9 kg·m/6.5 lb ft) for heat protector25. Install generator assembly.
Torque: 40 N·m (4.0 kg·m/29 lb ft) for ACG bracket
Torque: 40 N·m (4.0 kg·m/29 lb ft) between ACG and
bracket
Torque: 20 N·m (2.0 kg·m/14.5 lb ft) between ACG
and adjuster plate
26. Fix the A/C compressor bracket and install A/C
compressor.
Torque: 47 N·m (4.7 kg·m/34 lb ft) for A/C bracket
Torque: 20 N·m (2.0 kg·m/14.5 lb ft) for belt tensioner
27. Reconnect harness connector around cylinder
head.
28. Connect EGR vacuum hose.
29. Install oil level gauge guide assembly.
Tighten nuts lower portion and tighten bolt.
Torque: 20 N·m (2.0 kg·m/14.5 lb ft)
30. Install intercooler assembly.
Refer to “Intercooler” in this manual.
31. Install air duct between air cleaner and
turbocharger.
32. Fill engine coolant.
33. Reconnect battery.
For Europe
025R200007
For Europe
025R200006
1 7
2
3
4
5 6
010R200006

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

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 COOLING 6B – 5
ENGINE COOLANT CHANGE
PROCEDURE
1. To change engine coolant, make sure that the
engine is cool.
WARNING:
When the coolant is heated to a high temperature,
be sure not to loosen or remove the radiator cap.
Otherwise you might get scalded by hot vapor or
boiling water. To open the radiator cap, put a piece
of thick cloth on the cap and loosen the cap slowly
to reduce the pressure once the coolant has
become cooler.
2. Open radiator cap and drain the cooling system by
loosening the drain valve on the radiator and on the
cylinder body.
NOTE: For best results it is suggested that the engine
cooling system be flushed at least once a year. It is
advisable to flush the interior of the cooling system
including the radiator before using anti-freeze
(ethylene-glycol based).
Replace damaged rubber hoses as the engine anti-
freeze coolant is liable to leak out even minor cracks.
Isuzu recommends using Isuzu genuine anti-freeze
(ethylene-glycol based) or equivalent, for the cooling
system and not add any inhibitors or additives.
CAUTION:
A failure to correctly fill the engine cooling system
in changing or topping off coolant may sometimes
cause the coolant to overflow from the filler neck
even before the engine and radiator are completely
full.
If the engine runs under this condition, shortage of
coolant may possibly result in engine overheating.
To avoid such trouble, the following precautions
should be taken in filling the system.
3. To refill engine coolant, pour coolant up to filler neck
using a filling hose which is smaller in outside
diameter than the filler neck. Otherwise air between
the filler neck and the filling hose will block entry,
preventing the system from completely filling up.
4. Keep a filling rate of 9 liter/min. or less. Filling over
this maximum rate may force air inside the engine
and radiator.
And also, the coolant overflow will increase, making
it difficult to determine whether or not the system is
completely full.
5. After filling the system full, pull out the filling hose
and check to see if air trapped in the system is
dislodged and the coolant level goes down. Should
the coolant level go down, repeat topping-off until
there is no more drop in the coolant level.
6. Directly after filling the radiator, fill the reservoir to
the maximum level.
7. Install and tighten radiator cap and start the engine.
After idling for 2 to 3 minutes, stop the engine and
reopen radiator cap. If the water level is lower,
replenish.WARNING:
When the coolant is heated to a high temperature,
be sure not to loosen or remove the radiator cap.
Otherwise you might get scalded by hot vapor or
boiling water. To open the radiator cap, put a piece
of thick cloth on the cap and loosen the cap slowly
to reduce the pressure once the coolant has
become cooler.
8. After tightening radiator cap, warm up the engine at
about 2,000 rpm.
Set heater adjustment to the highest temperature
position, and let the coolant circulate also into
heater water system.
9. Check to see the thermostat has opened by the
needle position of a water thermometer, conduct a
5-minute idle again and stop the engine.
10. When the engine has been cooled, check filler neck
for water level and replenish if required. Should
extreme shortage of coolant be found, check the
coolant system and reservoir tank hose for leakage.
11. Fill the coolant into the reservoir tank up to “MAX”
line.

6B – 8 ENGINE COOLING
INSTALLATION
1. Thermostat
1) The jiggle valve of the thermostat must face the
cylinder head side.
2. Gasket
3. Install thermostat housing and tighten bolt to the
specified torque.
Torque: 20 N·m (2.0 kg·m/14.5 lb ft)
4. Reconnect water hose
1) Fill coolant to full level.
2) Reconnect battery ground cable.
5. Start the engine check for coolant leakage.

6B – 10 ENGINE COOLING
Checking for Coolant Leakage
1) Check the cooling system for leakage with the
radiator cap tester by applying 196.0 kPa (28.4 psi)
air pressure from filler neck to inside the radiator.
INSTALLATION
1. Radiator Assembly
1) Install rubber cushions on both sides of radiator
bottom.
2) Install radiator assembly with hose, taking care
not to damage the radiator core by a fan blade.
2. Bracket
1) Support the radiator upper tank with the bracket
and fix the radiator.
3. Reserve Tank Hose
4. Fan Guide, Lower
5. Radiator Hose
1) Connect inlet hose and outlet hose to the
engine.
2) Connect battery ground cable.
3) Pour coolant up to filler neck of radiator, and up
to MAX mark of reserve tank.
4) Start engine to warm up, and check for coolant
level. Replenish coolant if it does not reach the
radiator filler neck, and tighten the cap
completely.
110RS005
012RW080

6E±185 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Poor Fuel Economy Symptom

StepActionValue(s)Ye sNo
1DEFINITION:
Fuel economy, as measured by an actual road test, is
noticeably lower than expected. Also, economy is
noticeably lower than it was on this vehicle at one time,
as previously shown by an actual road test. (Larger than
standard tires will cause odometer readings to be
incorrect, and that may cause fuel economy to appear
poor when it is actually normal.)
Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
ÐVerify repairGo to Step 3
3Was a visual/physical check performed?
ÐGo to Step 4
Go to Visual/
Physical
Check
4Check owner's driving habits.

Is the A/C ªONº full time (defroster mode ªONº)?

Are tires at the correct pressure?

Are excessively heavy loads being carried?

Is acceleration too much, too often?

Is engine oil correct?
Was a problem found?
ÐGo to Step 5Go to Step 6
5Review the items in Step 4 with the customer and
advise as necessary.
Is the action complete?
ÐSystem OKÐ
61. Visually/physically check: Vacuum hoses for splits,
kinks, and improper connections and routing as
shown on the ªVehicle Emission Control
Informationº label.
2. If a problem is found, repair as necessary.
Was a repair required?
ÐVerify repairGo to Step 7
71. Remove and check the air filter element for dirt or for
restrictions. Refer to
Air Intake System.
2. Replace the air filter element if necessary.
Was a repair required?
ÐVerify repairGo to Step 8
81. Check for low engine coolant level. Refer to Engine
Cooling
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 9
91. Check for an incorrect or faulty engine thermostat.
Refer to
Engine Cooling.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 10
101. Check for low engine compression. Refer to Engine
Mechanical
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 11

6E±226
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
0018
Manifold Absolute Pressure (MAP) Sensor
The manifold absolute pressure (MAP) sensor responds
to changes in intake manifold pressure. The MAP sensor
signal voltage to the ECM varies from below 2 volts at idle
(high vacuum) to above 4 volts.
The MAP sensor is used to determine the following:

Boost pressure for injector control.

Barometric pressure (BARO).
If the ECM detects a voltage that is lower than the
possible range of the MAP sensor, DTC P0107 will be set.
A signal voltage higher than the possible range of the
sensor will set DTC P0108. An intermittent low or high
voltage will set DTC P1107 or DTC P1106, respectively.
The ECM can detect a shifted MAP sensor. The ECM
compares the MAP sensor signal to a calculated MAP
based on throttle position and various engine load factors.
If the ECM detects a MAP signal that varies excessively
above or below the calculated value, DTC P0106 will set.
Engine Control Module (ECM)
The engine control module (ECM) is located in the engine
room.
The ECM constantly observes the information from
various sensors. The ECM controls the systems that
affect vehicle performance. The ECM performs the
diagnostic function of the system. It can recognize
operational problems, alert the driver through the MIL
(Service Engine Soon lamp), and store diagnostic trouble
codes (DTCs). DTCs identify the problem areas to aid the
technician in making repairs.
ECM Function
The ECM supplies 5, 12 and 110 volts to power various
sensors or switches. The power is supplied through
resistances in the ECM which are so high in value that a
test light will not light when connected to the circuit. In
some cases, even an ordinary shop voltmeter will not give
an accurate reading because its resistance is too low.
Therefore, a digital voltmeter with at least 10 megohms
input impedance is required to ensure accurate voltage
readings. The ECM controls output circuits such as theinjectors, glow relays, etc., by controlling the ground or
the power feed circuit through transistors or through
either of the following two devices:

Output Driver Module (ODM)

Quad Driver Module (QDM)
ECM Components
The ECM is designed to maintain exhaust emission levels
to government mandated standards while providing
excellent driveability and fuel efficiency. The ECM
monitors numerous engine and vehicle functions via
electronic sensors such as the crankshaft position (CKP)
sensor, and vehicle speed sensor (VSS). The ECM also
controls certain engine operations through the following:

Fuel injector control

Rail pressure control
ECM Voltage Description
The ECM supplies a buffered voltage to various switches
and sensors. It can do this because resistance in the
ECM is so high in value that a test light may not illuminate
when connected to the circuit. An ordinary shop
voltmeter may not give an accurate reading because the
voltmeter input impedance is too low. Use a 10-megohm
input impedance digital voltmeter to assure accurate
voltage readings.
The input/output devices in the ECM include
analog-to-digital converters, signal buffers, counters,
and special drivers. The ECM controls most components
with electronic switches which complete a ground circuit
when turned ªON.º These switches are arranged in
groups of 4 and 7, called either a surface-mounted quad
driver module (QDM), which can independently control up
to 4 output terminals, or QDMs which can independently
control up to 7 outputs. Not all outputs are always used.
ECM Input/Outputs
Inputs ± Operating Conditions Read

Air Conditioning ªONº or ªOFFº

Engine Coolant Temperature

Crankshaft Position

Electronic Ignition

Manifold Absolute Pressure

Battery Voltage

Intake Throttle Position

Vehicle Speed

Fuel Temperature

Oil Temperature

Intake Air Temperature

EGR boost pressure

Oil rail pressure

Camshaft Position

Accelerator position
Outputs ± Systems Controlled

Exhaust Gas Recirculation (EGR)

Injector Control

QWS