Thread: Transmission temps before and after cooler

What's up guys. I want to see what others are experiencing. I have a built trans stock stall and have not been able to monitor temps due to my AF gauges being washed out for about a year. Finished up my build and had the gauges repaired. Also new dex6 fluid again due to shift kit install.

First few trips about 30-40 minutes of city driving 85* with ac on , temps peak about 205* , coolant around 177-185*
Installed an aux cooler , and it takes a bit longer to warm up (hangs around 165 for a while) but then creeps up to 185 and stays there.
A run or 2 and it peaks at 190*. Highest I seen so far. Is this normal ? Average ? Never used one before Thanks !

Ps I also have a smaller version of the same cooler , about half the size , was going to try for PS cooler like the police packages have ; but I don't see how or what it benefits.

I installed a OEM Trans Cooler off the 9C1 Cars on my 04 GTP. I would experience temps that were always higher than the 180* Thermostat that I have installed. However when I did the hose routing, I did not follow the OEM routing. From what I believe the trans cooler hits the OEM Rad before it come back to the trans. I installed it so that it hits the Rad, then cooler, and then back to the trans.

Temps stay about 20-30* on the highway, of course in traffic it will creep up to coolant temps with out airflow

I had a cooler (stock 92-95 Bonneville cooler), then did a built trans. Didn't monitor until after getting the trans done. I saw consistent 160F temps, once winter came, I had to bypass the cooler because I drive mostly highway and couldn't get to 160F

180° to 190° peak is about what I see after my cooler install.

http://www.grandprixforums.net/threa...n-fluid-cooler

http://www.grandprixforums.net/threads/91937-9C1-Transmission-Cooler-on-Grand-Prix

^^This is what I did for the trans cooler on my GTP. It was an actual 9C1 transmission cooler with oem lines and everything. Temp drop was about 15*, so nothing particularly awesome, but just a little extra.

I put a larger stacked plate cooler on the 04 Imp LS, and installed it standalone. Dropped temps considerably more.

So the rad heat soaks the trans or vice versa. I figured since the trans was seeing over 200 at times , the radiator would be the one taking on the extra Heat load helping keeping the trans cooler.

If a stand alone cooler is considerably cooler then I should re think that part

Yup run it in standalone and take the radiator out of the question.. The only time guys have issues with running it in standalone is like Bill mentioned... Those winter months but you can just block it, but I doubt this car is seeing snow.


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I wasn't running it stand alone. Trans simply didn't put out much heat. A good build puts out less heat, a heavy foot adds heat.

Did the Cadillac bent tube piece thing have a snap-on connector or threaded ?
I was browsing the parts book and couldn't find any , yet

I noticed a mild drop after I installed the trans cooler after radiator configuration (compared to stock). For some reason my car is running slightly warmer this summer and the trans temps have followed - maybe 10 degrees or so. Might be time for a coolant flush.

A standalone cooler would be a better option if you are looking for a big drop in temps. Assuming you aren't in a cold weather climate.

I currently am stock in the cooler/rad department. Last week it was 36*c (94*f) and I got my highest temp readings....




I was on the freeway a minute later (50-60mph); the coolant temp dropped to 195* within a few minutes, but the trans took about 10 minutes to get to 210*. A trans cooler is definatley needed.

Thanks for all the feedback. I was in the same situation as Chris ^ but with a 180* t stat , the temps would see about 188 heat soaked with AC on and trans around 206

so I'm happy to say it's been better with the cooler installed as it is. After a long drive it doesn't get past 190. My engine coolant is more stable - 177-183

Originally Posted by BillBoost37

... A good build puts out less heat, a heavy foot adds heat.

I've never seen my trans temps hit 200* (mabey 190* mabey) Usually only gets up to 140-160 after 40min drive. Iv got a stock cooler and tranny with an Intence s.k. Lite foot?

^thats really cold considering the rad is over *200 .....

Our tranny coolers are located on the cooler side of the radiator. The rad won't be at engine temp unless it's heat soaked with little air movement. I feel a lot of people overlook this. Just because the engine is at operating temp, that doesn't mean the rad is too.

Saw high temps on the interstate before trans cool install. at around 80 mph, i saw 210-215. then when traffic came and I started passing people, I saw a peak of 228, usually around 218. Trans cooler is now installed in series with the radiator, I haven't seen above 190 in hard driving with it being 85ish out. On a 3 hour trip to school going around 85, it sat at 180.

Originally Posted by chris99gtp

Saw high temps on the interstate before trans cool install. at around 80 mph, i saw 210-215. then when traffic came and I started passing people, I saw a peak of 228, usually around 218. Trans cooler is now installed in series with the radiator, I haven't seen above 190 in hard driving with it being 85ish out. On a 3 hour trip to school going around 85, it sat at 180.

Nice #'s. Kind of what I am hoping to see after my cooler install. Is the cooler installed before or after the rad? Any pics of your install?

It goes Trans>Radiator>Cooler>Trans.

with cooler @ 180 hahahhahahahahahha

I've noticed on my other (v8) car that the higher stall converter greatly added to my heat issues.

They also sell thermostatic valves that can bypass the cooler when it's cool out, and circulate thru it when it's up to temp.