Jeep Cherokee 2000 Service Manual - page 271
CONDITION
POSSIBLE CAUSES
CORRECTION
TEMPERATURE GAUGE READS
HIGH OR THE COOLANT
WARNING LAMP ILLUMINATES.
COOLANT MAY OR MAY NOT BE
LOST OR LEAKING FROM THE
COOLING SYSTEM (CONTINUED)
17. Viscous fan drive not operating
properly.
17. Check fan drive operation and
replace as necessary. Refer to
Viscous Fan Drive in this Group.
18. Electric cooling fan not
operating properly (vehicles
equipped with 2.5L/4.0L and air
conditioning
18. Check electric fan operation and
repair as necessary. Refer to
Electric Cooling Fan in this Group.
19. Cylinder head gasket leaking.
19. Check for cylinder head gasket
leaks. Refer to Cooling System-
Testing For Leaks in this Group. For
repair, refer to Group 9, Engines.
20. Heater core leaking.
20. Check heater core for leaks.
Refer to Group 24, Heating and Air
Conditioning. Repair as necessary.
TEMPERATURE GAUGE READING
IS INCONSISTENT (FLUCTUATES,
CYCLES OR IS ERRATIC)
1. On vehicles equipped with an
electric fan, the gauge may cycle
up and down. This is due to the
cycling of the electric radiator fan.
1. This is a normal condition. No
correction is necessary unless the
gauge cycles into the red (overheat)
zone. Refer to Electric Cooling Fan
Diagnosis and Testing in this group.
2. During cold weather operation,
with the heater blower in the high
position, the gauge reading may
drop slightly.
2. A normal condition. No correction
is necessary.
3. Temperature gauge or engine
mounted gauge sensor defective or
shorted. Also, corroded or loose
wiring in this circuit.
3. Check operation of gauge and
repair if necessary. Refer to Group
8E, Instrument Panel and Gauges.
4. Gauge reading rises when
vehicle is brought to a stop after
heavy use (engine still running)
4. A normal condition. No correction
is necessary. Gauge should return
to normal range after vehicle is
driven.
5. Gauge reading high after
re-starting a warmed up (hot)
engine.
5. A normal condition. No correction
is necessary. The gauge should
return to normal range after a few
minutes of engine operation.
6. Coolant level low in radiator (air
will build up in the cooling system
causing the thermostat to open
late).
6. Check and correct coolant leaks.
Refer to Cooling System-Testing for
leaks in this group.
7. Cylinder head gasket leaking
allowing exhaust gas to enter
cooling system causing a
thermostat to open late.
7. (a) Check for cylinder head
gasket leaks. Refer to Cooling
System-Testing for Leaks in this
group.
(b) Check for coolant in the engine
oil. Inspect for white steam emitting
from the exhaust system. Repair as
necessary.
7 - 14
COOLING SYSTEM
XJ
DIAGNOSIS AND TESTING (Continued)