97LT

Normally when i am driving my car in the country no long red lights or traffic my car normally runs right around 185 degrees. Yesterday when i was sitting in traffic (80 degrees F) My car temp. gauge started rising pretty quickly up to about 235 degrees. I had only been stop and rolling in traffic for about 5 minutes. The fastest i got was about 10 MPH at MOST! In that 5 min it had risen that high but as soon as i got going again 45-50 MPH the temp started dropping. Then got on the interstate 75-85 MPH it dropped back down to 185. Scared me pretty bad though sitting in traffic. That being said if i would have had to sit for longer than 5 minutes there is no telling how high the temp could have gotten. Am i worried about nothing or is this something that needs to be fixed. I am no mechanic and the only thing i could think of would be a new thermostat...? Also sorry if this is not supposed to be posted in this category im still new to this site. Thanks!

shoebox

Normal operation for the system as long as your fans are working.

Read the first paragraph of this.

SteveC

You also may want to try flushing the radiator.

cheapchevy

Hated this up/down swing in temp on my Camaro and my Saturns. If normal operation bugs you, might want to replace with 160 deg thermostat and get PCM tuned for fans to come on sooner and keep engine cooler.

DrRuckus13

Just flip the AC on if sitting in traffic. it will kick the fans on.

or... ride your 929 if its 80 and sunny !!

Guy Ligier

Yes, this exact same thing happened to me, it was a faulty 1-wire coolant temp sensor on the driver's side, just as shoebox said. At stop lights I kept seeing the temp dial creep up into the red, and no fans were turning on, I was freaking out! Replaced the 1-wire sensor, and found out I was never anywhere near overheating at all.
When using the A/C I was still worried that maybe the (3) relays or wiring to the fans were bad since they didn't kick on right away like before. Once again shoebox was right about how the fans won't be triggered if you don't have enough pressure in your A/C. Turns out I had a leaky compressor. With that changed and a new charge, the fans work perfectly normally, no danger of overheating! Thanks shoebox, you know your stuff!