Coolant Temperature Below Thermostat Regulating Temperature
â–¶ How to fix
Check thermostat Check engine coolant sensor
What you'll see
No driver-visible symptom recorded.
System reaction
Engine coolant temperature lower than expected
Diagnostic depth
Detection
The engine coolant temperature is lower than excpected during engine warmup
Possible cause
Thermostat stuck open or engine coolant temp sensor is not plausible.