1995 GT overheating -baffling

[alexthezephyr]

I have a 1995 Grand AM GT, 3.1L v6, auto, it has 150,500 on it. My car overheats like mad (260+) when driving for the first few minutes, then the temperature drops down to a little over 100. Then it will continue to randomly spike for, oh, 15 or so minutes. After that it will only heat up while idling. When I am at stoplights, sitting in my driveway, or what have you, it will heat up to 220, but when I rev the engine, or continue driving, it will fall back down to normal range. I am pretty sure that when it heats up that water is not circulating (heat goes cold). I have replaced the thermostat (replaced twice, just for good measure, as it didn't work after the first one), and I am pretty sure that it is neither the water pump nor the head gasket. Any ideas?

[gmack221]

sounds like you have air in the coolant system, thats usually what causes spiking like you mentioned.

[alexthezephyr]

i wish it were that simple, i bled the system pretty well after replacing the thermostat.

[Ricochet1]

Hello, I would like to know if you have had any luck with your overheating problems? I too have a 95 grand am gt with a 3.1 v6 that is overheating and I have not yet found a solution. The temperature guage will fluctuate from 150 deg to max and back down to 150 within a 2 mile stretch. I have replaced the thermostat, and the water pump. The person that I purchased it from said that they had a new radiator installed. I have bled the air out on numerous occasions and it is still overheating. I do have heat and the car runs fine. It does't seem to be missing. When it overheats, the water comes out of the resivoir cap. I have no problem changing the head gaskets and heads if thats what it takes. I just do not want to do that if that is not the problem.

Thank You for any help that you may be able to give me.

[alexthezephyr]

Originally Posted by Ricochet1

Hello, I would like to know if you have had any luck with your overheating problems? I too have a 95 grand am gt with a 3.1 v6 that is overheating and I have not yet found a solution. The temperature guage will fluctuate from 150 deg to max and back down to 150 within a 2 mile stretch. I have replaced the thermostat, and the water pump. The person that I purchased it from said that they had a new radiator installed. I have bled the air out on numerous occasions and it is still overheating. I do have heat and the car runs fine. It does't seem to be missing. When it overheats, the water comes out of the resivoir cap. I have no problem changing the head gaskets and heads if thats what it takes. I just do not want to do that if that is not the problem.

Thank You for any help that you may be able to give me.

I replaced the head gaskets and had to mill down a head - that seems to have taken care of the problem.

Best of luck to ya!