CONDITION
POSSIBLE CAUSES
CORRECTION
TEMPERATURE GAUGE
READING INCONSISTENT
( ERRATIC, CYCLES OR
FLUCTUATES)
1. Heavy duty cooling system, extream
cold ambient (outside) temperature or
heater blower motor in high position.
1. None. System operating normaly.
2. Temperature gauge or gauge sensor
defective.
2. Check gauge. (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER
- DIAGNOSIS AND TESTING)
3. Temporary heavy usage or load.
3. None. Normal condition.
4. Air traped in cooling system.
4. Fill cooling system (Refer to 7 -
COOLING - STANDARD
PROCEDURE).
5. Water pump
5. Replace water pump.
6. Air leak on suction side of water
pump.
6. Check for leak. (Refer to 7 -
COOLING - DIAGNOSIS AND
TESTING)
RADIATOR CAP LEAKING
STEAM AND /OR
COOLANT INTO
RESERVOIR BOTTLE.
(TEMPERATURE GAUGE
MAY READ HIGH)
1. Radiator cap defective.
1. Replace radiator cap.
2. Radiator neck surface damaged.
2. Replace radiator.
HOSE OR HOSES
COLLAPSE WHEN
ENGINE IS COOLING.
1. Vacuum created in cooling system on
engine cool-down is not being relieved
through coolant reservior/overflow
system.
1. Replace radiator cap, check vent
hose between radiator and reservoir
bottle for blockage also check reservoir
bottle vent for blockage.
NOISY FAN
1. Fan blade(s) loose, damaged.
1. Replace fan blade assembly.
2. Thermal viscous fan drive.
2. None. Normal condition.
3. Fan blades striking surrounding
objects.
3. Locate contact point and repair as
necessary.
4. Thermal viscous fan drive bearing.
4. Replace viscous fan drive assembly.
5. Obstructed air flow through radiator.
5. Remove obstruction.
INADEQUATE AIR
CONDITIONER
PERFORMANCE
(COOLING SYSTEM
SUSPECTED)
1. Radiator and/or A/C condenser air
flow obstructed.
1. Remove obstruction and/or clean.
2. Thermal viscous fan drive not
working.
2. Check fan drive. (Refer to 7 -
COOLING/ENGINE/FAN DRIVE
VISCOUS CLUTCH - DIAGNOSIS AND
TESTING)
3. Air seals around radiator damaged or
missing.
3. Inspect air seals, repair or replace as
necessary.
WG
COOLING - 2.7L DIESEL
7a - 3
COOLING - 2.7L DIESEL (Continued)