I was driving on the highway this weekend and suddenly my AC went from cold to ambient temp. Then my temperature gauge started to rise rapidly. It came very close to the "red" but never quite got there. I imediately turned the AC off and lowered my RPMs. Doing so I thought that my temp would go back down and stay down, but it went up and down for the rest of the drive.

The next day I didn't rev higher than 3500 RPM and there was no prob. This morning however I was driving to work and just rev'ed it up to 4-5k once and the temp began to rise. I've found that turning on the heat (vent) helps a bit but I'd like to not have to worry about it at all.

I replaced the thermostat with a 180 degree about a year an a half ago. Also, I've got plenty of coolant. Those are the extent of my diagnosis abilities, so anyone out there that might know, please help.

 

Check all of your ground wires. (chassis to valve cover, chassis to battery, and chassis to transmission) Did your AC belt break? if not, the ac "clutch" may have gone bad...

 

check the fan switch because your electric fan maybe not working correctly causing the engine to over heat

 

go change your thermo

 

Thanks for the suggestions. I worked on the car last night, and I checked my coolant level again. This time the reserve tank was empty. I then added coolant, and took it for a drive, reving it up to 7k several times, with no abnormal temp. rise. Thanks for the help guys.