Severity: Fix soon. Usually safe to drive for now.
The engine is taking too long to warm up, which almost always means the thermostat is stuck open and coolant is flowing through the radiator too early.
Check the coolant level first, then replace the thermostat — it is the cause in most cases.
Safe to drive, but fuel economy and heater performance suffer, and the engine wears faster when it never reaches temperature.
Generally safe to drive, but get it checked soon. Safe to drive, but fuel economy and heater performance suffer, and the engine wears faster when it never reaches temperature.
The most common causes are: Thermostat stuck open; Low coolant level; Failed coolant temperature sensor giving a wrong reading; Cooling fan running when it should not. A scan tool and a visual check of the parts above is where a technician starts.
Check the coolant level first, then replace the thermostat — it is the cause in most cases.
