Hello All,

I have a high mileage 88 gta with a 350 in it. I am running a 180 degree thermostat and as far as I can tell both fans are always on. It runs at about 185 190 while moving but I come to a stop and 1 to 2 minutes I am running north of 235 (digital dash so its an estimate I am afraid) Soon as I get moving it drops right back down. Ambient air temp is between 60 and 80 so far this year with medium humidity (North Alabama) It idles pretty low (less than 500rpm) when I am sitting still. Any Ideas where my problem might lie? Everything is stock on the car with aside from the thermostat. Tips and tricks welcome

 

one fan is regular fan for a certain temp, second one is overheat fan/a.c. fan. the fans would come on earlier with a different switch (iirc) but it is normal for your car to warm up while sitting in traffic. our cars dont have grilles so they bake themselves under the hood unless you're moving -- then the air dam scoops up air into the radiator.

 

If you have the digital dash then it gets to the line below the redline before he temp starts to drop again if I am sitting still. So I am guessing around 245-250. Does that seem appropriate? If so I wont worry much but the temp going between 180 and 250 in stop and go traffic seems pretty bad for the engine to me

Thanks a bunch for the reply.

 

If you trust the digital dash, you're setting yourself up for failure. Figure out if it's actually overheating before you get excited. People seem to like those Infrared thermometers, or you can temporarily hook up a cheap analog gauge, or look for other signs of a real problem, like the radiator boiling over. You might check if your fan(s) come on. Might take up to 230* before the fan kicks in. By design these cars run hot to lower emissions. Its not going to break things if it runs as designed. If the radiator is boiling over, filling the overflow tank past the full hot line, etc it's not working by design.

Got antifreeze in the radiator? Is it green or dirty mucky brown? is it full to the full Cold line on the overflow tank? Got air dam? Should hang down to about 4 inches above the ground. If its' missing, or completely destroyed, start there. Got a bunch of plastic baffling under the front end that guides air from under the nose up and through the radiator? Condenser fans all mashed over flat from that Wombat you ran down in a fit of rage? Might want to straighten those fins. Plague of Locusts stuck in the radiator fins? Hose em out. Still got the foam rubber blocks down the sides of the condenser/radiator support? Might want to make sure they're in the correct place. The idea is air needs to flow up and thru the radiator and down the trans tunnel and out the back.

 

If your car sits most of the time, it might be worth pulling the top bracket on the radiator, and looking for a mouse nest between the radiator and the air conditioning condenser.

I had a persistent heating issue with mine, because the previous owner mostly let the car sit...the mouse had made a nest that covered nearly the entire bottom half of the radiator with trash, but it wasn’t visible until I had to replace the radiator.

 

That plague of locusts thing isn't a joke. Previous owner of one of my cars must have driven thru a cloud that blacked out the sun. Every bit of space between the air filter and aircleaner was packed solid, noticed awhile back the condenser is packed with then too. Never really bothered to look, and this made it thru used car dealer detailing.

 

I got one of these radiator caps with a built in temperature gauge. Very handy for sanity checks.

 

Factory fan doesn't come on until 238 degrees. These cars were designed to run hot for emissions reasons so unless it's boiling over it's not overheating. I like the infrared thermostats so you can check various places to check temps.

 

That’s easily changed...it took a bit of time to find the proper part,, but I changed the sensor on mine to one that closes at 200. But then again, I don’t have to deal with emissions testing.