Service Diagnosis - Jeep 1987 Wrangler Workshop Manual

ENGINES
#P1
COOLING SYSTEMS
#P1
shaft seal or through incomplete sealing in the
coolant recovery system.
Combustion pressure may be forced into the
cooling system through a fracture in the cylinder
head gasket, though the passage is too small to
allow coolant to enter the combustion chamber.
NOTE: Immediately after shutdown, the engine
enters a condition known as heat soak. This is
caused by the cooling system being inoperative
while the engine temperature is still high. If the
coolant temperature rises above the boiling
point, expansion and pressure may push some
coolant out of the radiator overflow tube. If this
does not occur frequently, it is considered
normal.
Refer to the applicable diagnosis chart for
specific cooling system faults.
Service Diagnosis
Condition
Possible Cause
Correction
HIGH T E M P E R A T U R E
G A U G E I N D I C A T I O N -
OVERHEATING
(1) Coolant level low.
(2) Fan belt loose.
(1) Replenish coolant.
(2) Adjust fan belt tension.
(3) Radiator hose(s) collapsed.
(3) Replace hose(s).
(4) Radiator airflow blocked.
(4) Remove restriction (bug screen, fog
lamps, etc.)
(5) Faulty radiator cap.
(5) Replace radiator cap.
(6) Ignition timing incorrect.
(6) Adjust ignition timing.
(7) Idle speed low. (7) Adjust idle speed.
(8) Air trapped in cooling system. (8) Purge air.
(9) Heavy traffic driving. (9) Operate at fast idle in neutral
intermittently to cool engine.
(10) Incorrect cooling system
component(s) installed.
(10) Install proper component(s).
(11) Faulty thermostat.
(11) Replace thermostat.
81189A
B-183