Faulty coolant temp sensors. Replace them both. Double check your fan relays.

Answered by jough626
2 questions asked

I changed the sensor at the thermostat, not sure where the other one would be located. Fan come's on, but car still warms up beyond the safe zone. Thanks again for the help.

Response from mechanix
1 question asked

When you turn the heater on, even with no fan pushing the hot air, this provides another avenue for the hot liquid to flow and release its heat. When you shut of the heat you close that valve and thus the system becomes smaller and because of another problem the engine will run warmer and in your case much warmer and not good. I would check simple things like a collapsed hose. They can look good and still have blockage. Another is a radiator blockage.

Did you say that you replaced the engine thermostat or just the sensor located by the thermostat?

Answered by Bruce Hunt (expert)
3,803 answers provided

I replaced the thermostat. The upper and lower radiator hoses are hot when the car has been running, I would guess that they are fine because liquid is flowing through them to cause them to heat up. I'm gonna do another flush tomorrow. Thanks for the reply.

Response from mechanix
1 question asked