CONDITION
POSSIBLE CAUSES
CORRECTION
COOLANT LOSS TO THE
GROUND WITHOUT PRESSURE
CAP BLOWOFF. GAUGE READING
HIGH OR HOT
1. Coolant leaks in radiator, cooling
system hoses, water pump or
engine.
1. Pressure test and repair as
necessary. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
DETONATION OR PRE-IGNITION
(NOT CAUSED BY IGNITION
SYSTEM). GAUGE MAY OR MAY
NOT BE READING HIGH
1. Engine overheating.
1. Check reason for overheating
and repair as necessary.
2. Freeze point of coolant not
correct. Mixture is too rich or too
lean.
2. Check coolant concentration.
(Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
HOSE OR HOSES COLLAPSE
WHILE ENGINE IS RUNNING
1. Vacuum created in cooling
system on engine cool-down is not
being relieved through coolant
reserve/overflow system.
1. (a) Radiator cap relief valve
stuck. (Refer to 7 - COOLING/
ENGINE/RADIATOR PRESSURE
CAP - DIAGNOSIS AND TESTING).
Replace if necessary
(b) Hose between coolant
reserve/overflow tank and radiator is
kinked. Repair as necessary.
(c) Vent at coolant reserve/overflow
tank is plugged. Clean vent and
repair as necessary.
(d) Reserve/overflow tank is
internally blocked or plugged. Check
for blockage and repair as
necessary.
NOISY VISCOUS FAN/DRIVE
1. Fan blades loose.
1. Replace fan blade assembly.
(Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - REMOVAL)
2. Fan blades striking a surrounding
object.
2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or air
conditioning condenser.
3. Remove obstructions and/or
clean debris or insects from radiator
or A/C condenser.
4. Thermal viscous fan drive has
defective bearing.
4. Replace fan drive. Bearing is not
serviceable. (Refer to 7 - COOLING/
ENGINE/FAN DRIVE VISCOUS
CLUTCH - REMOVAL).
5. A certain amount of fan noise
may be evident on models
equipped with a thermal viscous fan
drive. Some of this noise is normal.
5. (Refer to 7 - COOLING/ENGINE/
FAN DRIVE VISCOUS CLUTCH -
DESCRIPTION) for an explanation
of normal fan noise.
7 - 12
COOLING
AN
COOLING (Continued)