Ok I have a 1989 Iroc Z with the T.P.I. 350. I recently had to put a new crank kit in the motor.

Ever since I got it back the car overheats when the A/C is on. If I turn the A/C off it cools down and runs nice and cool. Turn the A/C back on and the temp climbs again. It gets so hot it boils the water in the overflow bottle.

Yes I have checked and both cooling fans come on and run when the A/C is on and the single fan comes on when the A/C is off.

I replaced the thermostat yesterday thinking maybe that was the problem. Well nope, today I was driving it and it did it again. Its outside gurgling right now.

I dont know whats going on and nobody seems to be able to help me.

Please help

 

Mine does the same thing, its called Lousiana HEAT, just currious was it cooler outside before you installed the crank? Just aprox 10degrees outside makes a huge difference with mine, when it gets much above 90 out here in Georgia you have to really watch it. It helped mine alot by taking about all the ANTI FREEZE out to about 15% and then put a bottle of Water Wetter in and it keeps mine about 190 or less for a long time even when in traffic, but once it starts creeping up to about 210/220 the engine gets heat soaked and it takes a while to cool back down. But for the most part the W/W helped a bunch. Good Luck.

 

I will try that stuff. It never did this before the new crank kit. Thats why it has to be something that happened during the reinstall.

 

Maybe you have a trapped air bubble in the cooling system...?

 

Is there any updates on this issue. I am having the same/similar problem... only when the A/C is on