Thread: overheating

noob question, why do cars tend to overheat when the air conditioning is on in slow/stopped traffic? or what if it only overheated when going 65+ mph with the air con on?

Generally when you turn on the A/C system, it taxes the engine. Thats why a second fan on your radiator turns on to keep the engine cool since its running harder to rotate the A/C compressor. If you are seeing overheating issues when you turn on the A/C, I would assume that either your coolant levels aren't full, you may have a small coolant leak, or your A/C fan isn't turning on when your A/C is on.

If you haven't done this already, pop the hood and turn on your A/C to see if the fans kick on. It wouldn't hurt to see how full your coolant is. If you need help looking at it, you can bring it by whenever.