High Transmission Temps

[StevenBateman]

So about 2 years ago I got my cam, heads, stall put on the car and initially didn't have an aftermarket tranny cooler, so I got a custom one done from a local transmission shop. Seemed to work great for the first year, highest temps were about 180-190 max. So about a year ago I noticed my temps getting higher than normal and the transmission would go into a sort of limp mode and throw a CEL. I got the cooler checked out and everything was running fine, and was told because of the stall and the high heats, that driving around the city would cause the transmission to get too hot if I was out for too long. Now I brought the car out a little over 2 months ago and the transmission seems to heat up so quickly. I could let it sit all day, fire it up, then it'll hit 180 within 10-15 minutes of driving. Could it be a problem with the cooler? Not sure what else it could be... any help or advice would be appreciated.

[hammdo]

Cooler may not be big enough but, does it have a thermostat? 180° is not bad at all. Over 210° and I’d be looking for a bigger cooler. Stalls do create more heat and city driving does not help temps. What are your temps while highway driving?

With what I have, I road race in summer heat and it stays < 180°. I have the trucool 40k and it works... City driving i might see 160° in the summer - in Texas. Highway driving 150s°. I have a 6L90 Converter in my 6L80 so stall is factory — keep that in mind.

-Don

[StevenBateman]

Originally Posted by hammdo

Cooler may not be big enough but, does it have a thermostat? 180° is not bad at all. Over 210° and I’d be looking for a bigger cooler. Stalls do create more heat and city driving does not help temps. What are your temps while highway driving?

With what I have, I road race in summer heat and it stays < 180°. I have the trucool 40k and it works... City driving i might see 160° in the summer - in Texas. Highway driving 150s°. I have a 6L90 Converter in my 6L80 so stall is factory — keep that in mind.

-Don

I don't believe it has a thermostat, I'm just basing my temps of my gauges. Highway temps, if I'm on it for an extended period of time are around 150, they don't even reach 180.

[hammdo]

Occasional times around 210° wont be bad at all. Constantly over that and you change fluid more often.

I raced mine before the bigger cooler, got it over 250° at times. When we rebuilt it, it looked great — the 35R showed a bit of heat but that was it.

-Don

[GRNFLSH]

I 2nd Hammdo's comments, 180F isn't bad, especially if you're running a stall converter, but getting hot enough for limp mode is a concern. Also I've found that the factory trans temp aren't precise (on any car I've ever owned). I'm more comfortable pulling temps from PCM data. What source are you using for your temp reading?

I'm running cam, heads, and 3800 stall with an ADM cooler and summer time averages are 160-175F. I did log 179-180F after 5 back to back 1/4 mile runs in the heat.

[hammdo]

I had limp mode once racing at Eagles Canyon — too much torque registered. Stopped, turned off the car, turned ignition on, reset the dtc, restart, didn’t happen after that. Ambient was 40°. Strangest thing for it to happen at those temps. Trans was 150° when it happened too...

-Don

[StevenBateman]

Originally Posted by GRNFLSH

I 2nd Hammdo's comments, 180F isn't bad, especially if you're running a stall converter, but getting hot enough for limp mode is a concern. Also I've found that the factory trans temp aren't precise (on any car I've ever owned). I'm more comfortable pulling temps from PCM data. What source are you using for your temp reading?

I'm running cam, heads, and 3800 stall with an ADM cooler and summer time averages are 160-175F. I did log 179-180F after 5 back to back 1/4 mile runs in the heat.

It's not so much the 180 temp that concerns me, its how quickly it reaches it. It'll take like 15-20 minutes of driving to hit 180 after it sat all day in 15 celcius/59 farenheit, then slowly starts to creep up. It hasn't gone to a limp mode in a long time. My source for temp reading is just the gauge cluster that came with the car.

[John_C]

If temps are up, is it slipping?

I went with a fan cooled oil cooler.

This:

https://www.holley.com/products/cool...parts/FP820ERL

And if anyone wants to copy the setup.....

Brackets:

https://www.holley.com/products/cool...s/parts/800ERL

Did a Frostbit 40amp wiring harness.

https://www.holley.com/products/cool...ys/parts/FB403

Oil cooler adapters

https://www.holley.com/products/plum...ts/AT585106ERL

Speed-Seal Hose End Hose Size -6 Nut Size 6 Material Stainless Adjustable Low Profile 90

https://www.holley.com/products/plum...arts/609096ERL

Bowler -6an manifold

https://www.bowlertransmissions.com/...ifold-6l80cma/

-6an Speed-Seal Hose End Hose Size -6 Nut Size 6 Material Stainless Straight

https://www.holley.com/products/plum...arts/600196ERL

Speed-Seal Hose End Hose Size -3 Nut Size 3 Material Stainless Adjustable Low Profile 45

https://www.holley.com/products/plum...arts/604593ERL

Thread sealer

https://www.holley.com/products/plum.../parts/D024ERL

-6an line

https://www.holley.com/products/plum...arts/620006ERL

[StevenBateman]

Went to my local shop today and told me that the trans cooler that I'm running is more than likely too small for the set up that I'm running. He has a few modded trucks/cars in his shop and he highly recommended that i go with the Tru Cool 40K as that's what he runs in all his vehicles and says he has zero trans temp problems.

[StevenBateman]

Update, Tru Cool 40K installed and I could not be happier. Temps are staying low, even driving 30 minutes in stop and go traffic in 33 Celsius/91 Fahrenheit didn't even hit 180. Found one for 115$, so I'd say money well spent. Highly recommended!

[Bo White]

Trans temps are simular to engine temps. The cooler the trans fluid the better but if its under 200* most of the time your ok.

[StevenBateman]

Have had the Tru Cool for almost a week now and the temps barely even hit 170.