Jeep 200 Cherokee Service Manual page 302

XJ
DIAGNOSIS AND TESTING (Continued)
CONDITION
INADEQUATE HEATER
PERFORMANCE. MAY BE
ACCOMPANIED BY LOW
GAUGE READING
HEAT ODOR
STEAM IS COMING FROM
FRONT OF VEHICLE NEAR
GRILL AREA WHEN
WEATHER IS WET, ENGINE
IS WARMED UP AND
RUNNING, AND VEHICLE IS
STATIONARY.
TEMPERATURE GAUGE IS IN
NORMAL RANGE
COOLANT COLOR
2000 JEEP CHEROKEE
POSSIBLE CAUSES
1. Diesel engines, due to their inherent
efficiency are slower to warm up than
gasoline powered engines, and will
operate at lower temperatures when the
vehicle is unloaded.
2. Coolant level low.
3. Obstructions in heater hose fittings at
engine.
4. Heater hose kinked.
5. Water pump is not pumping water to
heater core. When the engine is fully
warmed up, both heater hoses should be
hot to the touch. If only one of the hoses
is hotk the water pump may not be
operating correctly. The accessory drive
belt may also be slipping causing poor
water pump operation.
1. Various heat shields are used at
certain drive line components. One or
more of these shields may be missing.
2. Is temperature gauge reading above
the normal range?
3. Is cooling fan operating correctly?
4. Has undercoating been applied to any
unnecessary component?
1. During wet weather, moisture (snow,
ice or rain condensation) on the radiator
will evaporate when the thermostat
opens. This opening allows heated water
into the radiator. When the moisture
contacts the hot radiator, steam may be
emitted. This usually occurs in cold
weather with no fan or airflow to blow it
away.
1. Coolant color is not necessarily an
indication of adequate corrosion or
temperatue protection. Do not rely on
coolant color for determining condition of
coolant.
COOLING SYSTEM
CORRECTION
1. The low gauge reading may be
normal. Refer to Thermostats in the
manual text for information. See
Thermostat Diagnosis - Diesel
Engine.
2. Refer to Testing Cooling System
For Leaks in the manual text.
Repair as necessary.
3. Remove heater hoses at both
ends and check for obstructions.
Repair as neccessary.
4. Located kinked area and repair
as necessary.
5. Refer to Water Pumps in this
group. Repair as necessary. If a
slipping belt is detected, refer to
Engine Accessory Drive Belts in this
group. Repair as necessary.
1. Locate missing shields and
replace or repair as necessary.
2. Refer to the previous
Temperature Gauge Reads High in
these Diagnosis Charts. Repair as
necessary.
3. Refer to Cooling System Fan in
this group for diagnosis. Repair as
necessary.
4. Clean undercoating as
necessary.
1. Occasional steam emitting from
this area is normal. No repair is
necessary.
1. Refer to Coolant in this group for
antifreeze tests. Adjust antifreeze-
to-water ratio as necessary.
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