Thread: 04 GP Temp gauge gets 1 notch over the middle? also loss of acceleration?

The hotter the weather, the warmer the car runs, and the slower it becomes.

Everything sounds normal for a stock thermostat. I bet your avg coolant temp is around 195-205º. And can get as high as 220º sitting in traffic.

The motor is not "hot" untill 240-260º, so your fine. And running the AC can increase temps.

I have a 180 thermostat and an alum finned trans pan.

A 160 may cause problems, so i have heard. I replaced my trans pan when I did my fluid change. I believe it helps keep the temp under 200. I don't know if 220 is something to worry about. Someone else here would know.

160 WILL cause problems on a stock tune.

as for the trans, get a seperate transmission cooler.

mine always ran around 180ish.

If you have the stock pcm fan programming. Your fans don't come on until around 216F low speed and 228F for high speed. so unless you are moving, expect temps to rise. The transmission cooler is in the radiator... keep that in mind.

FWIW I did two 8 hour runs in 90-95 degree heat the past week, through the hills of PA and they have some hills. The first leg was actually 85-90F outside and the trans averaged 190F with a 195F t stat. On the way back temps outside were 90-95F and the trans averaged 200F with one spike to 215F. 160F is considered the bottom of the operating temps for the trans. The high end is up around 230F.

Ooooo lookey what I found
Trasmision Automatic A Buick-Oldmobile 4T65E

Mine ran 190-195 this past week. My temp gauge runs on the first big mark, i think that's like a quarter.

guys..anyone wanting to learn even a little about the trans...check that link out.

Originally Posted by matt5112

Also have heard some claim there are no heat related failures with our transmission.

And then ive seen the advertising from companies who sell the coolers claiming it greatly extends life to run them around 150-160.

Someone go find proof and share.

No heat related failures? That's asinine.

You know of heat related failures? I think most of the time a separate cooler would be overkill.

They run too hot otherwise even in normal driving.

Originally Posted by BillBoost37

If you have the stock pcm fan programming. Your fans don't come on until around 216F low speed and 228F for high speed. so unless you are moving, expect temps to rise. The transmission cooler is in the radiator... keep that in mind.

FWIW I did two 8 hour runs in 90-95 degree heat the past week, through the hills of PA and they have some hills. The first leg was actually 85-90F outside and the trans averaged 190F with a 195F t stat. On the way back temps outside were 90-95F and the trans averaged 200F with one spike to 215F. 160F is considered the bottom of the operating temps for the trans. The high end is up around 230F.

Ooooo lookey what I found
Trasmision Automatic A Buick-Oldmobile 4T65E

I bought the day pass to download that. It looks to be a wealth of knowledge

A friend of mine has a 04 GTP with an oversize rad, and a 180 with a PCM tuned for it, he never goes above 191*

Originally Posted by acidcrashdburnd

A friend of mine has a 04 GTP with an oversize rad, and a 180 with a PCM tuned for it, he never goes above 191*

I have a stock radiator a 180 and a pcm and I don't go much above that. I have seen 195-196 on a 101 degree day.

Originally Posted by Sudden

I have a stock radiator a 180 and a pcm and I don't go much above that. I have seen 195-196 on a 101 degree day.

I saw 206* while I was coming out of Baltimore on I97 no traffic, it was just freaking hot 99* out, I was also cruising at 85-90.