Hey guys, got a question for you. I've got a 90 RS that I just purchased a few months ago. The car sat for 2+ years without even being started. In the last 2 weeks I've put a little over $2,000 getting it on the road. I flushed the radiator and replaced the hoses and water pump. The electric fan seems to run when I'm driving yet when I shut the car off, the fan goes off instantly and the car reaches almost 220 degrees. I don't even have to shut it off. If I'm stuck at a light for a few minutes the temp will start rising and if I put it in park the temp rises from 165 to 220. As soon as I start driving again it instantly goes back to normal. I don't have the slightest idea what to do and am hoping it's a simple fix. I have to keep the heat on almost all the time to keep it cool. Also, I'm getting a little bit of gray smoke when I start it and I'm losing about a quart of antifreeze a week from my reservoir but I don't see any leaks on the ground or smell antifreeze when I open the hood. Any thoughts?

 

Have you replaced the thermostat?

 

Thermostat maybe? My camaro overheated in the driveway in the snow. That turned out to be the issue. I had been having the same issue prior to replacing it. Also your coolant can't just disappear so you need to figure out where it is goes. If it is leaking out somewhere then you could have a simple low coolant level.

 

If it only gets to 220ish, it's not overheating. It was designed to operate like that. The fans don't turn on till the engine is baking (that's my opinion, and I'm sticking with it). If you want your engine to run cooler, you need to change your thermostat and possibly a temperature switch to kick the other fan on sooner. You do have two fans, right?

That's the easy part. You also need so adjustments made to your computers "programming" so that it doesn't think your car is never warmed up. Otherwise your gas mileage is likely to suk.

To be more specific:
My car's ECM turns the primary fan on when coolant temp is >223F. A non ECM controlled switch turns the secondary fan on at temps >238F. There are other things that can cause the fans to run, but those are the temperature thresholds for turning them on.

 

No I haven't. I plan on doing that this weekend. I probably should have when I changed the water pump but I thought it was working fine because when I put my hand on the upper radiator hose it was warm so it should be open right? I bought an engine temp switch and I'll replace that this weekend also. Any other thoughts?

 

No, I only have a single fan mounted in the center. I had thought about replacing that with dual fans but I didn't know if I would need to change the ECM. I was reading in the haynes manual and it shows I should have a 195 degree thermostat. I'm assuming that either I dont, or its stuck open. I can drive for an hour on the highway and the car will never get over 170 degrees but if I park in for 5 minutes and run in the store it will jump up to 220. That seemed awfully high to me but maybe it's not.

 

Hmm.....missed this the first time. Sounds suspiciously like a head gasket to me. I had a 350 one time that developed a crack in the metal ring around the combustion chamber. This let water slowly migrate from a nearby passage straight to the cylinder thru the center of the gasket if that makes sense to you. Slowly lost water with no sign of where, light puff of smoke out one side on startup, and eventually wild fluctuating temperature indications that were seemingly impossible.