Engine Fails To Reach Normal Operating Temperature LA3, LY9
Diagnostic Aids
The engine may fail to reach normal operating temperature due to an intermittent operation of one of the following components:
| • | The coolant bypass valve |
| • | The thermostat |
For electrical inspection of the coolant bypass solenoid, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Step | Action | Yes | No |
|---|---|---|---|
DEFINITION: Normal coolant temperature readings will be expected to vary from 92°C (198°F) and 107°C (225°F). | |||
1 | Did you perform the engine cooling diagnostic system check? | ||
2 | Verify that the engine fails to reach normal operating temperature. Is the engine failing to reach normal operating temperature? | Go to Diagnostic Aids | |
3 | Inspect the surge tank for low coolant. Is there a loss of coolant? | Go to Loss of Coolant | |
4 | Inspect for an inoperative coolant bypass valve. Refer to Coolant Bypass Valve Inoperative . Does the engine still fail to reach normal operating temperature? | ||
5 | Inspect the thermostat for proper operation. Refer to Thermostat Diagnosis . Does the thermostat operate properly? | ||
6 | Replace the thermostat. Refer to Engine Coolant Thermostat Replacement . Did you complete the repair? | -- | |
7 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | |
