Ok, I have a 97 Trans Am...has been running very well ever since I bought, put headers on it ect... I took out the fan relay in the fuse box because the fans were never coming on when the temp got around 210! I put a 160 thermostat in there and ghetto rigged a manual fan switch, it worked and that's all I care about, don't care much if it looks ugly under the hood! But around two or three weeks ago the car would start to overheat just randomly so I'd throw the fan switch on and it'd cool down. Then it started overheating after running for not even 5 minutes while driving, and now it is at the point where if I start it up drive down the road sit at a red light for a minute or so it's already over 210! And the fans are not coming on anymore with I flip the switch. There are no leaks in the radiator either. I have not started to look at anything yet, I just want to know what I should look for to start out! Check the fan switch? Drain the coolant, grounds for fans, thermostat, anything else? Thanks in advance for the help.

 

Bleed the coolant system see if it works.

 

Bleed the system, see if that helps. Do you have the fans wired up to run at full blast, or just one of them on?

 

Five minutes and it overheats? Do you have a temp thermometer? I doubt your car is getting that hot that quick. I would think there might be something wrong with your guage. It wont hurt to bleed the system again though. When you put in a lower thermostat, you should also have it tuned.

 

Did you happen to notice he's located in Fla? If there were air in the system it would eventually work it's way to the radiator where it would then lower the level of the coolant. The low coolant light would come on unless the coolant sensor were disconnected. So is the coolant sensor hooked up or not? Is the level low in the radiator?

Have you pulled the top cover off the radiator and looked between the condensor and the radiator for debris? Mine had a plastic grocery bag in there once.

Have you checked for a bad fuse on the circuit you have the fans installed? Have you checked to see if there is voltage getting to and then through the manual switch you installed?


Have what tuned?

 

I have the fans connected to run one fan on low. I am going to drain the system today, but it is not low at all. There is nothing stuck up in there, I check under there at least once a week for crap. The coolant light has been on non stop since I bought the car which means the sensor is most likely bad. I have not checked the voltage, I'll do that today tho! Thanks for the help

 

The low coolant light comes on for a bad sending unit as well. I just had to replace mine.

 

Put in a new fan relay and temp. sending unit and everything is working well for now.