2001 Cavalier Heater Issue
 

TROUBLESHOOTERS NEEDED!

The engine will warm up and run at normal temperature while stopped or at low speeds. The thermostat / engine tempdrops the faster I go in colder weather. This wasn't a problem before to this degree. I noticed it last year but only mild temperature fluctuations. Now the temp goes from 190 to non-registering (below 100). The check engine light came on and comes on regularly showing the 1)engine coolant level (level is ok) 2)Thermostat faulty 3)Thermostat sending unit. My only other guess was the radiator fan relay switch so I replaced that too. I did notice the fan was on and the engine was not up to temperature yet.

I changed the thermostat, thermostat sending unit and the cooling fan relay switch. Am I missing something? Like I said before, I notice the temperature swing during the winter but never to this degree. It's freezing in the carwhen I go to work!

Thanks in advance.

RE: 2001 Cavalier Heater Issue
 

put some cardboard in front of ur radiator
check you coolant to water mix
it might be getting to cold when u are running down the road and freezing in the radiator
how cold is it outside where you aare
or just unplug the fan and see if that helps
but if u unplug the fan make sure it doesnt over heat when u are in stop and go traffic

good luck

RE: 2001 Cavalier Heater Issue
 

Have you checked the rad cap ?? It may need replacing.