Chrysler 2004 Concorde Service Manual page 187

LH
COOLING (Continued)
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - COOLING SYSTEM
CONDITION
TEMPERATURE GAUGE
READING IS INCONSISTENT
(FLUCTUATES, CYCLES OR IS
ERRATIC).
PRESSURE CAP IS BLOWING
OFF STEAM AND/OR
COOLANT. TEMPERATURE
GAUGE READING MAY BE
ABOVE NORMAL BUT NOT
HIGH. COOLANT LEVEL MAY
BE HIGH IN COOLANT
RESERVE/OVERFLOW TANK.
POSSIBLE CAUSES
1. During cold weather operation
with the heater blower in the high
position, the gauge reading may
drop slightly. Fluctuation is also
influenced by loads, outside
temperature, and cycling of the air
conditioning system.
2. Temperature gauge or engine
sending unit 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
restarting a warmed-up (hot)
engine.
5. Coolant level low (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 thermostat
to open late.
7. Water pump impeller loose on
shaft.
8. Air leak on the suction side of
water pump allows air to build up in
cooling system causing thermostat
to open late.
1. Pressure relief valve in radiator
cap is defective, or was not
properly seated.
2. Incorrect cap was installed.
3. Incorrect coolant mixture.
4. System overfilled.
COOLING 7 - 3
CORRECTION
1. A normal condition. No correction is
necessary.
2. Check operation of gauge and repair
if necessary. Refer to INSTRUMENT
PANEL AND SYSTEMS.
3. A normal condition. No correction is
necessary. Gauge reading 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 Testing Cooling System for
Leaks in this section.
6. (a) Check for cylinder head gasket
leaks with a commercially available
block leak tester. Repair as necessary.
(b) Check for coolant in engine oil.
Inspect for white steam emitting from
exhaust system. Repair as necessary.
7. Check water pump and replace as
necessary. Refer to Water Pump
Removal in this section.
8. Locate leak and repair as necessary.
1. Check condition of radiator cap and
cap seal. Refer to Pressure Cap in this
group. Replace cap as necessary.
2. Replace cap as necessary.
3. Make sure a 50% by volume mixture
of coolant is used.
4. Ensure cold coolant level is between
MIN and MAX marks on coolant bottle.