2002 ISUZU AXIOM engine overheat

0B±6MAINTENANCE AND LUBRICATION
Always change the oil and the oil filter as soon as possible
after driving in a dust storm.
Engine Cooling System Inspection
Inspect the coolant/anti±freeze. If the coolant is dirty or
rusty, drain, flush and refill with new coolant. Keep coolant
at the proper mixture for proper freeze protection,
corrosion inhibitor level and best engine operating
temperature. Inspect hoses and replace if cracked,
swollen or deteriorated. Tighten the hose clamps if
equipped with screw±type clamps. Clean outside of
radiator and air conditioning condenser. Wash filler cap
and neck. To help ensure proper operation, a pressure
test of both the cooling system and the cap is also
recommended.
Exhaust System Inspection
Visually inspect the exhaust pipes, muffler, heat shields
and hangers for cracks, deterioration, or damage.
Be alert to any changes in the sound of the exhaust
system or any smell of fumes. These are signs the system
may be leaking or overheating. Repair the system at
once, if these conditions exist. (See also ªEngine Exhaust
Gas Safetyº and ªThree Way Catalytic Converterº in the
Owner's manual.)
Fuel Cap, Fuel Lines, and Fuel Tank
Inspection
Inspect the fuel tank, the fuel cap and the fuel lines every
60,000 miles (96,000 km) for damage which could cause
leakage.
Inspect the fuel cap and the gasket for correct sealing and
physical damage. Replace any damaged parts.
Drive Belt Inspection
Check the serpentine belt driving for cracks, fraying,
wear, and correct tension every 30,000 miles (48,000
km). Replace as necessary.
Wheel Alignment, Balance and Tires
Operation
Uneven or abnormal tire wear, or a pull right or left on a
straight and level road may show the need for a wheel
alignment. A vibration of the steering wheel or seat at
normal highway speeds means a wheel balancing is
needed. Check tire pressure when the tires are ªcoldº
(include the spare).
Maintain pressure as shown in the tire placard, which is
located on the driver's door lock pillar.
Steering System Operation
Be alert for any changes in steering operation. An
inspection or service is needed when the steering wheel
is harder to turn or has too much free play, or if there are
unusual sounds when turning or parking.
Brake Systems Operation
Watch for the ªBRAKEº light coming on. Other signs of
possible brake trouble are such things as repeated pulling
to one side when braking, unusual sounds when braking
or between brake applications, or increased brake pedaltravel. If you note one of these conditions, repair the
system at once.
For convenience, the following should be done when
wheels are removed for rotation: Inspect lines and hoses
for proper hookup, bindings, leaks, crack, chafing etc.
Inspect disc brake pads for wear and rotors for surface
condition.
Inspect other brake parts, including parking brake drums,
linings etc., at the same time. Check parking brake
adjustment.
Inspect the brakes more often if habit or conditions
result in frequent braking.
Parking Brake and Transmission Park
Mechanism Operation
Park on a fairly steep hill and hold the vehicle with the
parking brake only. This checks holding ability. On
automatic transmission vehicles, shifting from ªPº
position to the other positions cannot be made unless the
brake pedal is depressed when the key switch is in the
ªONº position or the engine is running.
WARNING: B E F O R E C H E C K I N G T H E S TA R T E R
SAFETY SWITCH OPERATION BELOW, BE SURE TO
HAVE ENOUGH ROOM AROUND THE VEHICLE.
THEN FIRMLY APPLY BOTH THE PARKING BRAKE
AND THE REGULAR BRAKE. DO NOT USE THE
ACCELERATOR PEDAL. IF THE ENGINE STARTS,
BE READY TO TURN OFF THE KEY PROMPTLY.
TAKE THESE PRECAUTIONS BECAUSE THE
VEHICLE COULD MOVE WITHOUT WARNING AND
POSSIBLY CAUSE PERSONAL INJURY OR
PROPERTY DAMAGE.
Starter Safety Switch Operation
Check by trying to start the engine in each gear while
setting the parking brake and the foot brake. The starter
should crank only in ªPº (Park) or ªNº (Neutral).
Accelerator Linkage Lubrication
Lubricate the accelerator pedal fulcrum pin with chassis
grease.
Steering and Suspension Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts or signs of
wear. Inspect power steering lines and hoses for proper
hookup, binding, leaks, cracks, chafing, etc.
Body and Chassis Lubrication
Lubricate the key lock cylinders, the hood latch, the hood
and door hinges, the door check link, the parking cable
guides, the underbody contact points, and the linkage.
Propeller Shaft Inspection and Lubrication
Check the propeller shaft flange±to±pinion bolts for
proper torque to 63 Nwm (46 lb ft) for front and rear
propeller shaft.

6A±11
ENGINE MECHANICAL (6VE1 3.5L)
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

6A±13
ENGINE MECHANICAL (6VE1 3.5L)
Troubleshooting Procedure for Slapping or Hitting etc Noise
The slapping sound stops when spark plug on bad
cylinder is shorted out.
Condition
Possible causeCorrection
Timing belt noiseTiming belt tension is incorrectReplace pusher or adjust the tension
pulley or replace timing belt
Tensioner bearing defectiveReplace
Timing belt defectiveReplace
Timing pulley defectiveReplace
Timing belt comes in contact with
timing coverReplace timing belt and timing cover
Valve noiseValve clearance incorrectReplace adjusting shim
Valve and valve guide seizedReplace valve and valve guide
Valve spring broken or weakenedReplace
Valve seat off±positionedCorrect
Camshaft worn outReplace
Crankshaft noiseCrankshaft end play excessive
(noise occurs when clutch is
engaged)Replace thrust bearing
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 tensioner or drive belt

6B±4
ENGINE COOLING (6VE1 3.5L)

Mixing ratio
Check the specific gravity of engine coolant in the
cooling system temperature ranges from 0
C to 50
C
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

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.

6E±34
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
dissatisfaction. The following list of non-vehicle faults
does not include every possible fault and may not apply
equally to all product lines.
Fuel Quality
Fuel quality is not a new issue for the automotive industry,
but its potential for turning on the MIL (ªCheck Engineº
lamp) with OBD II systems is new.
Fuel additives such as ªdry gasº and ªoctane enhancersº
may affect the performance of the fuel. If this results in an
incomplete combustion or a partial burn, it will show up as
a Misfire DTC P0300. The Reed Vapor Pressure of the
fuel can also create problems in the fuel system,
especially during the spring and fall months when severe
ambient temperature swings occur. A high Reed Vapor
Pressure could show up as a Fuel Trim DTC due to
excessive canister loading. High vapor pressures
generated in the fuel tank can also affect the Evaporative
Emission diagnostic as well.
Using fuel with the wrong octane rating for the vehicle
may cause driveability problems. Many of the major fuel
companies advertise that using ªpremiumº gasoline will
improve the performance of the vehicle. Most premium
fuels use alcohol to increase the octane rating of the fuel.
Although alcohol-enhanced fuels may raise the octane
rating, the fuel's ability to turn into vapor in cold
temperatures deteriorates. This may affect the starting
ability and cold driveability of the engine.
Low fuel levels can lead to fuel starvation, lean engine
operation, and eventually engine misfire.
Non-OEM Parts
All of the OBD II diagnostics have been calibrated to run
with OEM parts. Something as simple as a
high-performance exhaust system that affects exhaust
system back pressure could potentially interfere with the
operation of the EGR valve and thereby turn on the MIL
(ªCheck Engineº lamp). Small leaks in the exhaust
system near the post catalyst oxygen sensor can also
cause the MIL (ªCheck Engineº lamp) to turn on.
Aftermarket electronics, such as transceivers, stereos,
and anti-theft devices, may radiate EMI into the control
system if they are improperly installed. This may cause a
false sensor reading and turn on the MIL (ªCheck Engineº
lamp).
Environment
Temporary environmental conditions, such as localized
flooding, will have an effect on the vehicle ignition system.
If the ignition system is rain-soaked, it can temporarily
cause engine misfire and turn on the MIL (ªCheck Engineº
lamp).
Refueling
A new OBD II diagnostic was introduced in 1996 on some
vehicles. This diagnostic checks the integrity of the entire
evaporative emission system. If the vehicle is restarted
after refueling and the fuel cap is not secured correctly,
the on-board diagnostic system will sense this as a
system fault and turn on the MIL (ªCheck Engineº lamp)
with a DTC P0440.Vehicle Marshaling
The transportation of new vehicles from the assembly
plant to the dealership can involve as many as 60 key
cycles within 2 to 3 miles of driving. This type of operation
contributes to the fuel fouling of the spark plugs and will
turn on the MIL (ªCheck Engineº lamp) with a P0300
Misfire DTC.
Poor Vehicle Maintenance
The sensitivity of OBD II diagnostics will cause the MIL
(ªCheck Engineº lamp) to turn on if the vehicle is not
maintained properly. Restricted air filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD II. Poor vehicle
maintenance can't be classified as a ªnon-vehicle faultº,
but with the sensitivity of OBD II diagnostics, vehicle
maintenance schedules must be more closely followed.
Related System Faults
Many of the OBD II system diagnostics will not run if the
PCM detects a fault on a related system or component.
One example would be that if the PCM detected a Misfire
fault, the diagnostics on the catalytic converter would be
suspended until Misfire fault was repaired. If the Misfire
fault was severe enough, the catalytic converter could be
damaged due to overheating and would never set a
Catalyst DTC until the Misfire fault was repaired and the
Catalyst diagnostic was allowed to run to completion. If
this happens, the customer may have to make two trips to
the dealership in order to repair the vehicle.
Emissions Control Information Label
The engine compartment ªVehicle Emissions Control
Information Labelº contains important emission
specifications and setting procedures. In the upper left
corner is exhaust emission information. This identifies
the emission standard (Federal, California, or Canada) of
the engine, the displacement of the engine in liters, the
class of the vehicle, and the type of fuel metering system.
There is also an illustrated emission components and
vacuum hose schematic.
This label is located in the engine compartment of every
vehicle. If the label has been removed it should be
replaced. It can be ordered from Isuzu Dealership.
Visual / Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:

Inspect all vacuum hoses for pinches, cuts,
disconnections, and proper routing.

Inspect hoses that are difficult to see behind other
components.

6E±67
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
A/C Clutch Control Circuit Diagnosis

 
StepNo Ye s Value(s) Action
321. A/C compressor relay removed.
2. Connect a fused jumper at the A/C compressor
relay socket with either wire.
3. Engine idling.
4. A/C ªONº.
5. Blower ªONº.
Did the compressor magnetic clutch engage?
ÐGo to Step 33Go to Step 34
33Repair the A/C compressor relay.
Is the action complete?
ÐVerify repairÐ
34Check for an open circuit between the A/C compressor
relay and the A/C clutch.
Was an open circuit found?
ÐGo to Step 35Go to Step 36
35Repair the open circuit between the compressor Clutch
and the A/C compressor relay.
Is the action complete?
ÐVerify repairÐ
36Service the compressor clutch or replace the
compressor due to a faulty internal overheat switch.
Is the action complete?
ÐVerify repairÐ
371. Remove the A/C compressor relay.
2. Idle the engine.
Is the compressor clutch still engaged when A/C is not
selected?
ÐGo to Step 38Go to Step 39
38Repair the short to voltage between the A/C clutch and
A/C compressor relay.
Is the action complete?
ÐVerify repairÐ
391. Reinstall the A/C compressor relay.
2. Remove the A/C thermostat relay.
3. Engine idling.
Is the compressor clutch still engaged when A/C is not
selected?
ÐGo to Step 40Go to Step 42
40Use a DVM to check for a short to ground between the
A/C compressor relay and F4 of the PCM.
Was a short detected?
ÐGo to Step 41Go to Step 25
41Repair the short to ground between the PCM and A/C
compressor relay.
Is the action complete?
ÐVerify repairÐ
42Repair the short to ground between the A/C thermostat
relay and the electronic thermostat.
Is the action complete?
ÐVerify repairÐ

6E±514
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Detonation/Sparks Knock Symptoms

StepActionValue(s)Ye sNo
1DEFINITION:
A mild to severe ping, usually worse under acceleration.
The engine makes sharp metallic knocks that change
with throttle opening.
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
4If Tech 2 readings are normal (refer to Typical Scan
Values
) and there are no engine mechanical faults, fill
the fuel tank with a known quality gasoline that has a
minimum octane rating of 87 and re-evaluate the
vehicle performance.
Is detonation present?
ÐGo to Step 5Verify repair
51. Check the transmission range switch circuit. Use a
Tech 2 and be sure the Tech 2 indicates that the
vehicle is in drive with the gear selector in drive or
overdrive.
2. If a problem is found, diagnose and repair the
transmission range switch as necessary (refer to
4L30-E Automatic Transmission Diagnosis).
Was a problem found?
ÐVerify repairGo to Step 6
61. Check TCC operation. Refer to 4L30-E
Transmission Diagnosis
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 7
71. Check for obvious overheating problems:

Low engine coolant.

Restricted air flow to radiator, or restricted
water flow through radiator.

Correct coolant solution should be a 50/50 mix
of approved antifreeze/coolant and water.
Refer to
Engine Cooling.

EGR operation. Refer to
DTC P0401.

ION sensing module fault.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 8
81. Ignition ªOFFº.
2. Disconnect the ION sensing module.
3. Disconnect the PCM.
Is the action complete?
ÐGo to Step 9Ð
9Check the ION sensing harness between the PCM
(F68) and ION sensing module circuit (RED Wire) at
the Kl line harness connector.
Was a problem found?
ÐVerify repairGo to Step 10