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Cooling System Pinpoint Test 2: Engine Overheats

PINPOINT TEST 2 - ENGINE OVERHEATS

PINPOINT TEST 2 ENGINE OVERHEATS
STEP INSPECTION ACTION
1 CHECK THE ENGINE COOLANT LEVEL
NOTE:
  • If the engine is hot, allow the engine to cool before proceeding.

  • Key OFF.
    WARNING:
    • Never remove the radiator cap under any conditions while the engine is operating. Failure to follow these instructions could result in personal injury and/or damage to the cooling system or engine. To avoid having scalding hot coolant or steam blow out of the radiator, use extreme care when removing the radiator cap from a hot radiator. Wait until the engine has cooled, then wrap a thick cloth around the radiator cap and turn it slowly to the first stop. Step back while the pressure is released from the cooling system. When you are certain all the pressure has been released, press down on the radiator cap (with a cloth), turn and remove.
  • Check the engine coolant level at the coolant recovery reservoir.
  • Is the engine coolant OK? 
Yes Go to next step.
No Refill the engine coolant at the coolant recovery reservoir.
See COOLING SYSTEM PINPOINT TEST 1: LOSS OF COOLANT  .
2 CHECK THE COOLANT CONDITION
Yes Go to next step.
No Flush the engine cooling system.
See ENGINE COOLANT FLUSHING - 2.3L for 2.3L engine.
See ENGINE COOLANT FLUSHING - 3.0L for 3.0L engine.
See ENGINE COOLANT FLUSHING - 4.0L for 4.0L engine.
Test the system for normal operation.
3 CHECK FOR AN AIRFLOW OBSTRUCTION
  • Inspect the A/C condenser core and radiator for obstructions such as leaves or dirt.
  • Is there an obstruction? 
Yes Remove the obstruction. Clean the A/C condenser core and radiator.
Test the system for normal operation.
No Go to next step.
4 CHECK THE THERMOSTAT OPERATION
  • Start the engine and allow the engine to run for ten minutes.
  • Feel the inlet and outlet heater hoses and the underside of the upper radiator hose.
  • Are the upper radiator hose and the heater hoses cold? 
Yes Replace the thermostat.
See WATER PUMP REMOVAL/INSTALLATION - 2.3L for the 2.3L engine.

See WATER PUMP REMOVAL/INSTALLATION - 3.0L for the 3.0L engine.

See WATER PUMP REMOVAL/INSTALLATION - 4.0L for the 4.0L engine.


Test the system for normal operation.
No Go to next step.
5 CHECK THE COOLING FAN OPERATION
  • Key OFF.
  • Check cooling fan.
  • Is the cooling fan operation OK? 
Yes See SYMPTOM TROUBLESHOOTING CHART - ENGINE MECHANICAL  for diagnosis and testing of the engine.
No Replace the fan component determined to be faulty. Test the system for normal operation.