Engine Coolant Temperature / Engine Oil Temperature Correlation

Common symptoms

What you'll notice

• Check the engine coolant and oil levels to ensure they are within the recommended range.
• Inspect the thermostat and replace if malfunctioning or stuck in the closed position.
• Perform a thorough inspection of the cooling system for any leaks or blockages.
• Clean or replace the engine oil cooler if it is found to be clogged or damaged.
• In rare cases, there may be an issue with the Engine Control Module (ECM) or sensors, requiring diagnostic testing and potential replacement.

Common causes

Most likely first

1. Faulty engine coolant temperature sensor
2. Faulty engine oil temperature sensor
3. Low engine coolant level
4. Restricted engine oil flow
5. Faulty engine control module (ECM)

How to diagnose & fix

Work through it in order

1. Engine overheating
2. Engine misfires
3. Poor fuel efficiency
4. Smoke or steam coming from the engine
5. Stalling or rough idling