Hello all, Ive posted before about this issue and still having the same issue, I have a 86 Trans Am with 305 TPI, whats happening is anytime while driving the temp guage goes past 220 and will go anywhere between 220 and the red but usually in between the two, sometimes a little higher, I orginally thought it was only doing it while going fast but it seems to do it whenever I drive, When Im just stopped like at a light or in the driveway and let the car idle it goes back down to 220, I replaced the air dam because it was missing and it still seems to be doing it, other stuff i replaced was the thermostat, waterpump radiator, and I still dont think its the head because no white steam, no water in the oil, and im not losing coolant..... Well today i was sitting in the car with it ideling trying to figure out what it could possibly be and i heard the fan kick on and the temp gauge was a little past the 220 mark and soon as it got back down to 220 it cut back off..... Shouldnt the fan come on before 220 and is it normal for it to go off when it gets back down 220 or a little lower then that, and if you dont think its the fan, Does anyone else have any other ideas?????????

 

thats normal. Theres are some upgrades modifications if you're interested that can bring your temps to 190* or down to 170*. 220-230* is stock temps.

 

that would be great..... but it usually goes past 230 while driving then drops back down when im stopped and at what temp should the electic cooling fan come on... do you know???

 

http://www.superchevy.com/tech/0502s...ing/index.html

 

Is the car actually overheating or does the temp gauge just go out of whack? At what temp is the coolant fan kicking on? I would check that first...maybe you just need to change out your coolant temp sensor? If you are still unhappy, try using a lower temp tstat instead of the OE. :-)

 

Im having the same issue, it overheats and will die on me sometimes, but its only after driving it awhile, ive got a brnd new thermostat, water pump, radiator, and new sensors, so would it be that my fans arent kicking on at all? cause i know they work cause i have one of those GM scanners that flashes my trouble codes and when i plug that in and turn my ignition my fans do turn on but i havent actually checked to see if they turn on when my engine is running, cause my hoses are hot, my coolant was smoking out of the overflow resovior once i took the cap off. So wouldit be my fans not kicking in when they are supposed to? cause my temp gauge does like to fluctuate a lot but i can tell that its overheating cause you can feel the heat a couple feet away from the car before popping the hood.

 

You say driving for a while...is it stop and go, or highway? I don't think the fan runs when you are above 35 mph. I would check if your air dam is under the car and clean the crap in front of your radiator. There could be leaves, trash, ect blocking air flow.

 

Average is 60mph, but thats only for 15 min tops then i shut the engine off. But its a stop and go plus highway i guess. But now that you mentioned the leaves, i think the previous owner added their own fog lights cause they sit on either side of the camaro frint grill. so that would restrict some airflow, but i rebuilt the engine and before the rebuild it never overheated...

 

so i ran it for like five minutes and it made it up to 220 and the fans kicked on around then so i guess they do work, now i turned on my heater and it actually( according to the tach) fluctuated my RPMs by about 200.... but it was still getting hotter....

 

The factory setting for the fans to come on is around 220. With TPI you can reprogram the comp for one to come on earlier if running dual fans. The other one is controlled by the fan switch in the pass head. Do they both run?

 

yeah they both run. and yeah im running dual fans

 

This is basic, but are you purging the system? You know "burping" it.
You have the radiator cap off and start the car and wait until the thermostat opens up, then you keep topping off the coolant and letting the air bubbles get out. Once you see no more air bubbles surfacing put the cap back on.
Because if you have bubbles in the coolant system it is going to get hot, very quick.
Just maybe you forgot to check that.

 

i have not yet burpedthe system, but i have figured out that my upper hose is piping hot, but my lower is only warm.... its not the water pump is it? caus it is still getting hot so i know its running through the system...

 

Try burping the system. That's one of the basic things. Because if you have numerous air bubbles in the coolant it is for sure for sure going to overheat!

 

well it doesnt overheat anymore, i did burp the system, and also i moved the heater hose with that pressure valve or bleeder valve on it to the highest point on the engine and it runs great now, no overheating whatsoever.

 

Good to hear.