needaimport

my car will overheat when i turn on the a/c, why is that?

driving in houston heat w/o a/c is horrible.

the car only overheats if my a/c is turned on for a while. itll spike all the way up and then go down a little (but still hotter than usual) and go up again etc etc etc.

ive been told that the a/c shouoldnt affect anyhting.

TIA

The_Todd

The a/c compressor when it turns on puts a load on the engine and creates heat. Also when you run the condensor that usually displaces some heat too...all that added to your engine will create more heat to the entire system but your car should not overheat since your water pump/thermostat and radiator control that.

I would look into the following in this order:

your radiator fluid levels
any cracks or leaks in your cooling system
that your radiator fan is turning on
relays to fan are operable
your thermostat is opening up

BTW is your radiator a single or dual core?

needaimport

dunno, its a 94 civic and i got a $99 replacement radiator sometime.

ill get to checking those, thanks.

Crazydave

Depending on the A/C setup, it may turn the radiator fan on as well, which will help keep the engine coolant in check.

Frozen E

Check your T-Stat