Last night, cruising the interstate (70 mph give or take) my transmission temp spiked to 228*F. The temp outside was right around 90* in moderate traffic. Within the last couple months I've had the fluid and filter changed @ 92,000mi. Prior to this, the temps would regularly hit 220's - now they hover right around 201-206 and spike to 213 after a pass just cruising in open cool air down the road. In the past, I've taken an IR thermometer and shot it on the tranny and the case was about 30* cooler than what my DIC was indicating. Haven't done this in a while though. I also feel no slip or hesitation in the drivetrain.

I should note that the tranny fluid/filter change was done at a dealership by a trusted mechanic and he noted no abnormalties whatsoever. However, after they pulled up a query about normal transmission operating temps, thier GM computer said I have nothing to worry about until I hit 280* ! Even though my GM Owners manual says 170-200. Given this info, what would cause a transmission to run at an elevated temp or is the temp sensor faulty perhaps because 30* cooler and these temps are right in line with what they should be?

Any ideas are appreciated as I'd rather find the root cause of this rather than slap a bandaid of a tranny cooler over it but never diagnose the real problem.

_________________
2005 Grand Prix GT - SPO Spoiler, Tips, Grilles, Sills, Mats, SE Front Fascia, GMPP F/R STB's W/ Don's Brackets, GMPP RTA's & GMPP Rear Sway Bar

Have you upgraded to the 180 t-stat? That will help to some degree with the trans temps. As for the small spike in temp - that could be a few things, worn part that has not adjusted to the fluid change and is causing extra heat, clutch getting worn (common), extra load on the drive train ( sticky brakes ).

_________________
2004 Grand Prix GT AGGRESSOR
PRJ PCM, Custom Exhaust, 180 stat, FWI Custom Intake, DIC upgrade.

I'm currently running a 195* stat. I may drop to a 180 but I'll need to track down a computer to change my fan kick on speeds. I can't advise on the worn parts or clutch. However, I just replaced pads, rotors and fluid on all 4 corners and I know the brakes are good to go. Along those lines, the entire car is empty other than my 220lbs driving.

_________________
2005 Grand Prix GT - SPO Spoiler, Tips, Grilles, Sills, Mats, SE Front Fascia, GMPP F/R STB's W/ Don's Brackets, GMPP RTA's & GMPP Rear Sway Bar

To be honest the 180 T stat will probably help you out, I was hitting the 208s on the trans but with the t-stat and the fans activated I dont see above 194 during heavy driving, and 167 nominal.

_________________
2004 Grand Prix GT AGGRESSOR
PRJ PCM, Custom Exhaust, 180 stat, FWI Custom Intake, DIC upgrade.

My high tranny temps were caused by a worn bearing in the tranny. The fluid was leaking past the bearing and not getting to the gears to cool them off. Thus the reason for my second tranny rebuild. Both the dealership that fixed it the first time and the tranny shop that fixed it the second time recommended a cooler. I have one, but still haven't put it on. Can't find the time.

I have a 180 and my fans are reprogrammed, and I still got high temps.

_________________


3.5" MPS, 1.84 Rockers, 3" DP, Frt PEM, 39lb Injs., PowrTuner, Wizair
14.07@ 98.85mph 2.180 60'

my tranny was just overhauled.....seems like they pretty much replaced the whole thing, i still get 213 crusing at 75 on the highway right after the rebuild. when i lost fourth gear lasw weekend i got up to about 240 so i stopped to let it cool. then finished a short distance to my destination, had to drive home from boston to just past albany ny with gears 1,2,3 and i ran about 63 tranny got up to 223 so we stopped in lee mass to let it cool off a bit then we finished out trip. the dealer that just replaced the tranny is giving me the run around about a rental when they just replaced 4th gear and thats what im missing again.

_________________
bigbrew08

Hey blackwood, where did you get the cooler?