My Oldsmobile 95 overheats in 15 minutes and Idol but when I'm driving it down the road as long as I don't have to stop it will cool down considerably is it mean I have a faulty fan or faulty thermostat

What is your question?

If I'm driving non-stop it stays cool down but if I have to leave it in idle for 15 minutes or longer it shoots up into the red danger zone

What makes this problem better or worse?

Driving the car without having to stop and start

How long has your 1995 Oldsmobile 88 had this problem?

Since i got the car two weeks ago