Thread: Overheating at slow speeds and idle.

I've read the other threads about this subject but still can't seem to find the answer to my problem and was looking for some fresh ideas. I have a 07 GP GT, when i sit at idle or stop-and-go traffic, my temp gauge climbs like a squirrel up a tree into the red zone, yet when i drive for a min or so it cools back down. I've replaced the t-stat, water pump, and temp sensor, and have no leaks or air in the system. When i turn on the a/c, both fans turn on but at the low speed. I've also checked the harness from the fans back to the relays and there are no apparent damage to the wiring. Plz tell me what i'm missing and what i can do to rectify the situation. Sorry to repeat things that have already been described. Thanks in advance

samething happend to mine and i had a coolant leak

I'm using prestone yellow, i tested again today and i know the fans arent turning on, (forgot to mention that), but there's absolutely no leaks, anywhere. someone had posted on another thread that when he unplugged the coolant temp sensor that the fans turned on and stayed on until he turned the car off, thought i would give this a shot, and sure enough, the fans kicked on at high speed, cooled the motor like it was supposed to but, when i plugged it back in the fans shut off again and still dont turn on at the correct temp. the only thing i could think of is that i have something going wrong the PCM maybe? I also replaced the relays and they all check out fine as well as every fuse that could have anything to do with it. Thanks for the attention. =D

is it possible your temp sensor is bad.. if it works while the sensor is out, it must not be sending the right signal while its in to turn the fans one.

and another thing that you might want to check is the motor on the back of the electric fan. make sure its not bad. on my gf's hyundai elantra 2 weeks ago her temp sensor went out and it had the same problem your explaining. the fans would turn on with the bad sensor but they wouldn't stay running. and id have to hit the motor or manually spin the fan to kick start it. so i ended up replacing the motor and the sensor and everything is kosher now.

I replaced the temp sensor twice and the fans are working properly, pulled them out and tested them on a bench top. all the voltage, resistance, etc. is fine and they spin freely as they should. another thing i noticed is when i unplug the sensor and the fans run like they should(as stated in my second post), when i plug the sensor back in, if the car is at normal temp or below thats when that fans shut off. i let it get a bit hotter that normal and tried it and the fans stayed on till it cooled back to normal then turned off, but when it got hot again they wouldnt turn back on unless i unplugged the sensor again. Im completely lost and cant think of anything else.