mjkin4x4

I just bought a 1993 5.0 and am having a problem with it overheating. A little background: it has BBK headers (not wrapped with any heat-shield), aluminum radiator, and the fan has been changed (prior to my purchase)(mounts directly to the water pump, has not been upgraded to elec). I just replaced the thermostat with a 195 degree stat, and replaced the coolant temp switch. There are no leaks in the cooling system, its at correct coolant level, water pump SEEMS to be operating fine. The car regulates temp fine when I'm on an open road, even at speeds as low as 15 or 25 mph. When the vehicle is not moving, at idle, such as in a parking lot or drive thru, the temperature starts climbing and will not cool down until I get back on the road, or shut it down. I'm thinking it may need a higher flow fan to cool the liquid residing in the radiator--may just be pushing hot water back into the system before it gets a chance to cool down. However, am wondering if anyone has any other ideas before I drop money on unnecessary mods. Anyone have similar issues? Suggestions?

91hatchgt

Did it have the problem before you installed the new thermostat? If it did then I would suggest making sure that the system is properly burped. If it has air in the system it can cause similar problems. Maybe do a radiator flush if you have not. As it may need new fluids. Those are a few cheap things to check, if not, then I would suggest putting a clutch fan back on it, or upgrading to a Black Magic 5.0 fan. Good luck.

mjkin4x4

Thanks for the suggestions and the fan recommendation. It did have a problem before the thermostat swap. The old stat was a 180 degree, but did not regulate at all. The only way I could keep the car cool was to overdrive the conditions (higher gear, slower speeds to keep really low RPM while letting low speed fresh air through the front end). I'll definately try to flush the system first. Thanks again.

mjr46

you'll either need the stock clutch fan set up back on or upgrade it to an electric fan that pulls enough cfm