2001 v6es galant with 43k miles on it;I was driving in heavy traffic and the AC on when all of a sudden the AC air started to get warmer, I looked down and saw that my temperature gauge was almost redlining. I shut off the AC rolled down the windows and was about to turn on the heather when the traffic sped up to 30 MPH and the temperature guage dropped quickly to operating temp( i never turned on the heater). There are two stop signs near my house 3 blocks apart within 2 minutes from the first stop to my house as I was pulling into my driveway the temp shot up again. I turned off the AC and let the car idle as that happened it dropped to normal op temp again.
I have checked the coolant level, no coolant in my oil, and no steam out the tail pipe. I have never seen a car heat up and cool down so quickly and so inconsistently. a few hours later after the engine cooled I started it up with AC and it ran for 20 minutes no issues. I then started to drive and BAM it heated up again... ANy ideas? I thought T-stat at first but now I dont know.