New challenge...Came out to the Jeep this morning to let it warm up. After about 10 mins of it running I came out to leave and the temp was in the red. Put it in drive and took off and the temp immediately went down to normal operating range. Water pump is brand new, temp sensor and coolant as well. Any ideas? As long as I'm moving, it stays in the normal range. I also noticed it starting to do this if I'm in line at a fast food place for longer than a few minutes...

 

Air bubble in the system??????????????

 

had a similar problem in my mom's old car, and in her car it was the headgasket

 

maybe fan clutch.. fan may not be pulling in enough air while your sitting still? i dont know much about this stuff but im just throwing it out there. good luck.

 

Man I hope the head gasket isn't going bad. I wondered if I didn't have the system burped all the way, hopefully it's just that. The electric fan does come on though, although I don't feel it comes on as soon as it should. Guess I'll try to see if I can more air out. Any other ways other than revving it up with the rad cap off and adding fluid?

 

air in the system... but feel the radiator with your hand. see if you have cold spots after operating temperature is reached.