Symptom Troubleshooting Chart - Engine Cooling System
SYMPTOM TROUBLESHOOTING CHART - ENGINE COOLING SYSTEM
| Problem |
Possible Cause |
Action |
| Loss of engine coolant |
- Radiator.
- Thermostat housing assembly.
- Heater control valve.
- Transmission Oil cooler.
- Water pump seal.
- Radiator hoses.
- Heater hoses.
- Heater core.
- Engine gaskets.
- Degas bottle
|
|
| The engine overheats |
- Water thermostat.
- Airlock in the system.
- Water pump.
- Internal engine coolant leak.
- Radiator.
- Radiator airflow obstruction.
- Heater core.
- Cooling fan(s).
- Pressure relief cap.
|
|
| The engine does not reach normal operating temperature |
|
|
| The engine cooling fan(s) are inoperative/incorrect operation. |
- Circuitry open/shorted
- Engine cooling fan relay
- Engine cooling fan motor
- Powertrain control module (PCM)
|
|
| The block heater does not operate correctly |
- Block heater power cable.
- Block heater.
|
- DISCONNECT the power cable from the block heater.
- CHECK the resistance in all three power cable circuits. If the resistance is greater than 5 ohms in any circuit, replace the power cable. If the resistance is less than 5 ohms in all three circuits, replace the block heater.
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