mdooley

If AC is turned off, ie ac fan not spinning, engine overheats to 120 degrees in minutes. When ac is on, car stays at 90 degrees. What could cause this?

hachiroku

do you have coolant? check that and if you have no leaks you might have a blown headgasket due to headbolt failure.

Plutoe

Very strange if the AC was off and the engine goes over 102--the fan should come on as the ECU watches the coolant sensor an actuates the fan---I'd look at the thermostat and sensor----same with the AC, but the fan should only come on if the refrig temp gets way high and or the coolant is way high!!

mdooley

Thank you everyone who responded. The water pump pulley was not spinning freely and seized up. I replaced it and that solved the overheating.

hachiroku

glad to hear!