Dodge dakota 2002 Service Manual page 301

7 - 14 COOLING
COOLING (Continued)
CONDITION
Temperature gauge reading is
inconsistent (flucttuates, cycles
or is erratic)
PRESSURE CAP IS BLOWING
OFF STEAM AND/OR
COOLANT TO COOLANT TANK.
TEMPERATURE GAUGE
READING MAY BE ABOVE
NORMAL BUT NOT HIGH.
COOLANT LEVEL MAY BE
HIGH IN COOLANT RESERVE/
OVERFLOW TANK
COOLANT LOSS TO THE
GROUND WITHOUT
PRESSURE CAP BLOWOFF.
GAUGE READING HIGH OR
HOT
POSSIBLE CAUSES
1. During cold weather
operation, with the heater blower
in the high position, the gauge
reading may drop slightly.
2. Temperature gauge or engine
mounted gauge sensor defective
or shorted. Also, corroded or
loose wiring in this circuit.
3. Gauge reading rises when
vehicle is brought to a stop after
heavy use (engine still running)
4. Gauge reading high after
re-starting a warmed up (hot)
engine.
5. Coolant level low in radiator
(air will build up in the cooling
system causing the thermostat
to open late).
6. Cylinder head gasket leaking
allowing exhaust gas to enter
cooling system causing a
thermostat to open late.
7. Water pump impeller loose on
shaft.
8. Loose accessory drive belt.
(water pump slipping)
9. Air leak on the suction side of
the water pump allows air to
build up in cooling system
causing thermostat to open late.
1. Pressure relief valve in
radiator cap is defective.
1. Coolant leaks in radiator,
cooling system hoses, water
pump or engine.
CORRECTION
1. A normal condition. No correction
necessary.
2. Check operation of gauge and repair if
necessary. (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING).
3. A normal condition. No correction is
necessary. Gauge should return to normal
range after vehicle is driven.
4. A normal condition. No correction is
necessary. The gauge should return to
normal range after a few minutes of
engine operation.
5. Check and correct coolant leaks. (Refer
to 7 - COOLING - DIAGNOSIS AND
TESTING).
6. (a) Check for cylinder head gasket
leaks. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
(b) Check for coolant in the engine oil.
Inspect for white steam emitting from the
exhaust system. Repair as necessary.
7. Check water pump and replace as
necessary. (Refer to 7 - COOLING/
ENGINE/WATER PUMP - REMOVAL).
8. (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - DIAGNOSIS AND
TESTING). Check and correct as
necessary.
9. Locate leak and repair as necessary.
1. Check condition of radiator cap and cap
seals. (Refer to 7 - COOLING/ENGINE/
RADIATOR PRESSURE CAP -
DIAGNOSIS AND TESTING). Replace cap
as necessary.
1. Pressure test and repair as necessary.
(Refer to 7 - COOLING - DIAGNOSIS
AND TESTING).
DR