Page 858 of 2100

6A±48
ENGINE MECHANICAL (6VE1 3.5L)
9. Install air conditioner compressor to engine and
tighten to the specified torque.
Torque :
M8 bolts : 22 N´m (16 lb ft)
M10 bolts : 43 N´m (32 lb ft)
10. Install power steering pump, tighten fixing bolt to the
specified torque.
Torque :
M8 bolts : 22N´m (16 lb ft)
M10 bolts : 46 N´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) Idle Pulley
(8) 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 throttle position sensor harness
connector.
025RY001
Legend
(1) Throttle Position Sensor Connector
(2) Throttle Valve Assembly
27. Reconnect manifold absolute pressure sensor
harness connectors.
28. Reconnect ion sensing module connectors as shown
in the illustration.
060RY00111
Legend
(1) Green Connector
(2) Blue Connector
(3) Identification Mark (6VE1 Engine Only)
29. Install engine hood to the original position.
Refer to installation procedure for Body section in
this manual.
Page 906 of 2100
6B±2
ENGINE COOLING (6VE1 3.5L)
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
the radiator.
Water Pump
The EC pump is a centrifugal impeller type and is driven
by a timing belt.
030RS001
Page 907 of 2100
ENGINE COOLING (6VE1 3.5L)6B±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 ~ 17.0 psi) pressure. (No oil cooler provided for
M/T)
110RW023
Antifreeze 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
NOTE: An t if r e e ze s o lu t io n + Water = Total cooling
system capacity.
Total Cooling System Capacity
A/T 10.0Lit (2.64Us gal)
B06RW002
Page 908 of 2100

6B±4
ENGINE COOLING (6VE1 3.5L)
Mixing ratio
Check the specific gravity of engine coolant in the
cooling system temperature ranges from 0C to 50C
using a suction type hydrometer, then determine the
density of the engine coolant by referring to the table.
B06RW003
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
Page 909 of 2100

ENGINE COOLING (6VE1 3.5L)6B±5
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 ªMINº
and ªMAXº lines of reserve tank when the engine is cold.
If low, check for leakage and add EC up to the ªMAXº 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: T O AV O I D T H E D A N G E R O F B E I N G
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 ªMAXº line when the engine
is cold.
6. Block the drive wheels and firmly apply the parking
brake. Shift an automatic transmission to ªPº (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 ªMAXº 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.
Page 910 of 2100

6B±6
ENGINE COOLING (6VE1 3.5L)
Water Pump
Water Pump and Associated Parts
030RS002
Legend
(1) Timing Belt
(2) Idle Pulley(3) Water Pump Assembly
(4) Gasket
Removal
1. Disconnect battery ground cable.
2. Drain coolant.
3. Radiator hose (on inlet pipe side).
4. Remove timing belt. Refer to ªTiming Beltº in this
manual.
5. Remove Idle pulley.
6. Remove water pump assembly.
7. Remove gasket.
Inspection
Make necessary repair and parts replacement if extreme
wear or damage is found during inspection. Should any of
the following problems occur, the entire water pump
assembly must be replaced.
Crack in the water pump body
EC leakage from the seal unit
Play or abnormal noise in the bearing
Cracks or corrosion in the impeller
Installation
1. Install gasket, clean the mating surface of gasket
before installation.
2. Install water pump assembly and tighten bolts to the
specified torque.
Torque: 25 N´m (18 lb ft)
Tightening order
The tightening order are in the illustrate.NOTE: To prevent the oil leakage, apply the LOCTITE
262 or an equivalent, to the arrow marked fixing bolt
thread.
030RW008
3. Idle pulley
Install idle pulley and tighten bolt to the specified
torque.
Torque: 52 N´m (38 lb ft)
4. Timing belt
Install timing belt. Refer to timing belt installation
step in ªTiming Beltº in this manual.
5. Connect radiator inlet hose and replenish EC.
6. Connect battery ground cable.
Page 911 of 2100

ENGINE COOLING (6VE1 3.5L)6B±7
Thermostat
Thermostat and Associated Parts
031RW001
Legend
(1) Thermostat Housing
(2) Thermostat
(3) Outlet Pipe
Removal
1. Disconnect battery ground cable.
2. Drain engine coolant from the radiator and engine.
3. Disconnect radiator hose from the inlet pipe.
4. Remove thermostat housing.
5. Remove thermostat(2).
Inspection
Suspend the thermostat in a water±filled container using
thin wire. Place a thermometer next to the thermostat.
Do not directly heat the thermostat.
Gradually increase the water temperature. Stir the water
so that the entire water is same temperature.
031RS003Confirm the temperature when the valve first begins to
open.
Valve opening temperature 74.5C ~ 78.5C
(166.1F ~ 173.3F)
Confirm the temperature when the valve is fully opened.
Valve full open temperature and lift More than
8.5mm (0.33 in) at 90C (194F)
Make necessary repair and parts replacement if extreme
wear or damage is found during inspection.
Installation
1. Install thermostat into the outlet pipe(4) making sure
that the air hole is in the up position.
2. Install thermostat housing and tighten bolts to the
specified torque.
Torque: 25 N´m (18 lb ft)
3. Installation rubber hose.
4. Replenish engine coolant (EC).
5. Start engine and check for EC leakage.
Page 913 of 2100

ENGINE COOLING (6VE1 3.5L)6B±9
6. Disconnect the reserve tank hose(4) from radiator.
110RX001
7. Lift up and remove the radiator assembly with hose,
taking care not to damage the radiator core with a fan
blade.
8. Remove rubber cushions on both sides at the bottom.
Inspection
Radiator Cap
Measure the valve opening pressure of the pressurizing
valve with a radiator filler cap tester.
Replace the cap if the valve opening pressure is outside
the standard range.
Valve opening pressure kPa (psi) 93.3 ~ 122.7
(13.5 ~17.8)
Cap tester: J±24460±01
Adapter: J±33984±A
Check the condition of the vacuum valve in the center of
the valve seat side of the cap. If considerable rust or dirt is
found, or if the valve seat cannot be moved by hand, clean
or replace the cap.
Valve opening vacuum kPa (psi) 0 ~ 6.9 (0 ~ 1.0)
110RS006
Radiator Core
1. A bent fin may result in reduced ventilation and
overheating may occur. All bent fins must be
straightened. Pay close attention to the base of the fin
when it is being straightened.
2. Remove all dust, bugs and other foreign material.
Flushing the Radiator
Thoroughly wash the inside of the radiator and the engine
coolant passages with cold water and mild detergent.
Remove all signs of scale and rust.
Cooling System Leakage Check
Use a radiator cap tester to force air into the radiator
through the filler neck at the specified pressure of 150 kPa
(22 psi) with a cap tester:
Leakage from the radiator
Leakage from the coolant pump
Leakage from the water hoses
Check the rubber hoses for swelling.