My car, A 2008 Sedan. Overheats when the AC compressor runs. It usually takes about 15 minutes or so to happen, after that, the temp gauge starts to creep up.

I had an 2005 coupe that did something similar, but it only did it when it was hot outside and if I wasnt moving quick enough to get air flow through the radiator.

This car even does it at highway speeds, even when it's not all that hot outside.

Once I turn the compressor off, it goes back to normal....

Any suggestions? Compressor is new, along with a new pressure switch and the fan is new as well. I'm thinking maybe it's a relay or something, but I'm not sure.

Any suggestions are appreciated.

 

When you turn your A/C on does the fan kick on too? A/C condensers have a lot of heat to get rid of, if something is keeping the fans from running the heat will go straight to the radiator.

 

^ ya make sure both your fans are working, and your coolant is topped off

 

Make sure your fans and spinning at the appropriate speed too. My original OEM fan would still work, but only spun really slow and I'd buy quality parts too. I had a cheapo brand that the motors literally burnt out and had to do the job again.

 

Fan is new, and both appear to be running

 

Sounds like you're low on coolant. Don't just check at the reservoir, you need to pop the cap and look inside the radiator, the radiator should be full 100% to the top.

Obviously wait for the car to cool, don't take the cap off when it's hot unless you know what you're doing otherwise you will probably end up badly burned.

 

Coolant is topped off