CONDITION
POSSIBLE CAUSES
CORRECTION
2. Is the temperature gauge
connected to the temperature gauge
coolant sensor on the engine?
2. Check the engine
temperature sensor connector
in the engine compartment.
3. Is the temperature gauge
operating OK?
3. Check gauge operation.
Repair as necessary.
4. Coolant level low in cold ambient
temperatures accompanied with poor
heater performance.
4. Check coolant level in the
coolant tank. Inspect system for
leaks. Repair leaks as
necessary. Refer to the Coolant
section for WARNINGS and
precautions before removing
the pressure cap.
5. Improper operation of internal
heater doors or heater controls.
5. Inspect heater and repair as
necessary. Refer to Heating
and Air Conditioning for
procedures.
TEMPERATURE GAUGE
READS HIGH. COOLANT
MAY OR MAY NOT BE
LOST OR LEAKING FROM
COOLING SYSTEM
1. Trailer is being towed, a steep hill
is being climbed, vehicle is operated
in slow moving traffic, or engine is
being idled with very high ambient
(outside) temperature and the air
conditioning is on. Higher altitudes
could aggravate these conditions.
1. This may be a temporary
condition and repair is not
necessary. Turn off the air
conditioning and attempt to
drive the vehicle without any of
the previous conditions.
Observe the temperature
gauge. The gauge should return
to the normal range. If the
gauge does not return to
normal range, determine the
cause for the overheating and
repair.
2. Temperature gauge reading
incorrectly.
2. Check gauge. Refer to I/P
group.
3. Coolant low in coolant tank and
radiator.
3. Check for coolant leaks and
repair as necessary.
4. Pressure cap not installed tightly.
If cap is loose, boiling point of
coolant will be lowered.
4. Tighten cap.
5. Poor seals at pressure/vent cap.
5. (a) Check condition of cap
and cap seals. (b) Check
condition of coolant tank filler
neck. Make sure it does not
leak pressure.
6. Freeze point of antifreeze not
correct. Mixture may be too rich.
6. Check antifreeze. Adjust
antifreeze-to-water ratio as
required.
7. Coolant not flowing through
system.
7. Check for coolant flow in
coolant tank with engine warm
and thermostat open. Coolant
should be observed flowing
through the tank. If flow is not
observed, determine reason for
lack of flow and repair as
necessary.
7 - 14
COOLING
KJ