Overheating (details included)

I have a 1994 Pontiac Grand Prix 3.1 w/ app. 109,000 miles on it. I purchased this car a few months ago, and have no idea of any of the work done to it in the past... here is my problem...

My temp gage just recently started going into "the red" - first time was this weekend, and as soon as I saw it, I started to pull off to the side of the road, but as I did so, the temp immediately dropped back down to it's normal range. I did not have any additional trouble for the rest of the trip.

However, this morning, on my way into work, the car once again got too hot, and this time, pulling off to the side did not immediately cool it down. It DOES cool down, but not when it should. I have checked, and the fan turns on, but again, not when it should... It lets the vehicle get far too warm before sensing a need to kick on.

Does this sound like it could be a thermostat problem?? I plan to replace the thermostat tonight after work, but wondered if anyone else has had a similar problem and found it to be something else...

Let me know...
Thanks!!

I had the same problem with my car, you should try flushing the radiator and changing the thermostat and see what happens. If the same problem occur try changing you temp sensor. That should do it right there

[QUOTE=johnc623]I have a 1994 Pontiac Grand Prix 3.1 w/ app. 109,000 miles on it. I purchased this car a few months ago, and have no idea of any of the work done to it in the past... here is my problem...

My temp gage just recently started going into "the red" - first time was this weekend, and as soon as I saw it, I started to pull off to the side of the road, but as I did so, the temp immediately dropped back down to it's normal range. I did not have any additional trouble for the rest of the trip.

However, this morning, on my way into work, the car once again got too hot, and this time, pulling off to the side did not immediately cool it down. It DOES cool down, but not when it should. I have checked, and the fan turns on, but again, not when it should... It lets the vehicle get far too warm before sensing a need to kick on.

Does this sound like it could be a thermostat problem?? I plan to replace the thermostat tonight after work, but wondered if anyone else has had a similar problem and found it to be something else...----------------------------------------------------------------------------------------------------------------------------------------------------------I also just went through this with my 95 se..I changed t-stat and cts and it ran cooler but still hot .I bought a new water pump from autozone $20 and flushed the radiator and it made a drastic improvement .now the car wont run past 200 degrees. Hope this helps..good luck...

I had the same problem for 3 years now....Just this summer i finally hard wired a switch into the car to just toggle the non-a/c fan on and off.

It wasnt to much work and i just flip it on when i get stuck in traffic etc..... Havent had any problems since.

For info on how to, just reply and i will give u the ins and outs!

E

Eraser -- Your idea to hard wire the driver side fan sounds like something I would like to pursue. If you could post the process you used, that would be great. Sounds lot cheaper than changing the PCM as I have alreay eliminated all other components in my effort to deal with this problem. Seems that operating temps are all over the map with the 3.1. Thanks

actually. the temperature sensor should aleviate the problem. change the thermostat.. also, clean out the area between your a/c condenser and the radiator. make sure there is good flow of air through there.

alright i have the same problem and wut i was told was that i have a somewut blowen head gasket and that in my motor when it is runinbg it creats steam and when that steam hits the temp sensor it makes it go up but when u turn the car off it goes away cuz the steam loeses pressure and cools down.
so wut im gonna do it replace my head gaskets, i have already replaces my thermostat and my temp sensor and completle flushed my cooling systemand none of them did anything but temporay fix it but it all comes back

I had a 94 GP and had the same problem with it all of a sudden overheating and sky rocketing really fast. I assumed a blown head gasket. Checked oil and it was a little milky so went and looked at the head gaskets, they were fine and had the heads pressurized for any cracks and those were fine. According to guy that tested the heads he said that it is kind of a common problem with the 3.1 and 3.4 and that with how the intake sits in there it can sometimes loosen up the bolts that are on the intake and let it leak coolant in.

Doesn't sound like the same problem but could be possible, if nothing seems to work I would just tighten down the intake a little and see if that helps at all.