Jeep cherokee 2000 Service Manual page 255

XJ
DIAGNOSIS AND TESTING (Continued)
CONDITION
TEMPERATURE GAUGE READS
HIGH OR THE COOLANT
WARNING LAMP ILLUMINATES.
COOLANT MAY OR MAY NOT BE
LOST OR LEAKING FROM THE
COOLING SYSTEM (CONTINUED)
POSSIBLE CAUSES
6. Poor seals at the radiator cap.
7. Coolant level low in radiator but
not in coolant reserve/overflow
tank. This means the radiator is not
drawing coolant from the coolant
reserve/overflow tank as the engine
cools
8. Incorrect coolant concentration
9. Coolant not flowing through
system
10. Radiator or A/C condenser fins
are dirty or clogged.
11. Radiator core is corroded or
plugged.
12. Aftermarket A/C installed
without proper radiator.
13. Fuel or ignition system
problems.
14. Dragging brakes.
15. Bug screen or cardboard is
being used, reducing airflow.
16. Thermostat partially or
completely shut.
COOLING SYSTEM
CORRECTION
6. (a) Check condition of cap and
cap seals. Refer to Radiator Cap.
Replace cap if necessary.
(b) Check condition of radiator filler
neck. If neck is bent or damaged,
replace radiator.
7. (a) Check condition of radiator
cap and cap seals. Refer to
Radiator Cap in this Group. Replace
cap if necessary.
(b) Check condition of radiator filler
neck. If neck is bent or damaged,
replace radiator.
(c) Check condition of the hose from
the radiator to the coolant tank. It
should fit tight at both ends without
any kinks or tears. Replace hose if
necessary.
(d) Check coolant reserve/overflow
tank and tanks hoses for blockage.
Repair as necessary.
8. Check coolant. Refer to Coolant
section in this Group for correct
coolant/water mixture ratio.
9. Check for coolant flow at radiator
filler neck with some coolant
removed, engine warm and
thermostat open. Coolant should be
observed flowing through radiator. If
flow is not observed, determine area
of obstruction and repair as
necessary.
10. Remove insects and debris.
Refer to Radiator Cleaning in this
Group.
11. Have radiator re-cored or
replaced.
12. Install proper radiator.
13. Refer to Fuel and Ignition
System Groups for diagnosis.
14. Check and correct as
necessary. Refer to Group 5,
Brakes for correct procedures.
15. Remove bug screen or
cardboard.
16. Check thermostat operation and
replace as necessary. Refer to
Thermostats in this Group.
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