I have a 2008 Honda Civic si that overheats only with ac on. Where should I start looking?
Check that cooling fans are operating properly, they should all be running when the AC is turned on. Is temperature normal when the AC is off (gauge no more than halfway up), or is it always running a bit hot?
It runs at normal operating temperature. I drove for maybe 30 min and it started to overheat, but as soon as I turn off the ac, the temp starts to drop. Only one fan is on at all time.
How many fans do you have? They should all run with the AC. Another issue would be the radiator partly clogged; really any weakness in the cooling system will be aggravated by running the air conditioning.
I have 2 fans but only one turns on with the ac
That could be your problem right there.
Thank you for your help