I got an 01 s4. I've had if for almost 2 years. The timing belt was done on it last year. It has 114k on it. My temp guage sometimes says it's cold even after driving for hours. I'll look it and it will be all the way at the bottom like it hasnt moved then sometimes it goes up to normal operating temps. Also my car doesn't blow good heat until I get moving. I believe thermostat was changed when the timing belt was done... Plz help and thx

 

You might try purging the cooling system of air. No heat until you are moving would indicate possibly having air in the system.

I think that the guage problem is indicative of a bad coolant temp sensor, which is about $25 and very easy to change yourself. Our A6 4.2 had the same symptom and a new sensor cured it.

Ken

 

Hey, thanks for the reply!! I thought it might be the coolant sensor myself. I've read that it could also cause a bad idle? My cars idle is a little rough too. The sensor is a easy replace I'll try that but as far as purging my system. Never done that, is it easy to do?