Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Check for an incorrect or faulty surge tank cap. Is the surge tank cap incorrect or faulty? | -- | Go to Step 2 | Go to Step 3 |
2 | Replace the surge tank cap. Is there still a coolant loss? | 103 kPa (15 psi) | Go to Step 3 | System OK |
3 |
Is there still a coolant loss? | -- | Go to Step 4 | System OK |
4 | Check the heater core for leakage. Is the heater core leaking? | -- | Go to Step 5 | Go to Step 6 |
5 | Replace the heater core. Refer to Heater Core Replacement in Heating, Ventilation and Air Conditioning. Is there still a loss of coolant? | -- | Go to Step 6 | System OK |
6 | Start the engine and inspect. Is there excessive white smoke from the exhaust and/or does the engine idle rough? | -- | Go to Step 10 | Go to Step 7 |
7 | Road test the vehicle and allow the engine to reach full operating temperature. Does the engine overheat? | -- | Go to Engine Overheating | Go to Step 8 |
8 | Remove the oil level indicator stick and inspect. Is there engine coolant or a creamy/milky substance on the engine oil level indicator? | -- | Go to Step 9 | Go to Step 1 |
9 |
Important: Ensure that the cause of the creamy or milky substance is not caused by short drive cycles or a faulty thermostat. Either of these conditions will cause creamy or milky deposits to form in the engine oil because the engine cannot reach full operating temperature in order to dissipate the condensation/moisture. Does the engine reach full operating temperature during all of the vehicle drive cycles? | -- | Go to Step 10 | |
10 | The probable cause of the coolant loss is an engine internal coolant leak. If the spark plug electrodes or the porcelain surrounding the spark plug electrodes exhibit signs of coolant, replace the applicable cylinder heads or cylinder head gaskets. Did you complete the repair? | -- | Go to Step 11 | |
11 |
Is there still a coolant loss? | -- | Go to Step 1 | System OK |
