SeeYaSucker

I just swapped the M6 in my car to an A4 with 3500 converter, I used a PermaCool 24,000 cooler and since my car was an M6 my radiator does not have the factory cooler for the trans, highway temps are never above 125 and in town stop and go temps are never above 170, however my wifes car is a factory A4 car with the same cooler in the same spot used in conjuction with the factory cooler and her temps are considerably higher, I am just wondering if the factory cooler is actually heating the fluid from the hot antifreeze in the Radiator. I am going to bypass the factory cooler in her car and see if the Temps indeed do drop.

slowpoke96z28

iTrader: (2)

yep, it sure ir heating it up. tell your wife if she bypasses the radiator cooler, her temps will be lower too. thank you for posting this. i hope everyone with tranny heat problems with external coolers that refuse to bypass their radiator coolers reads this.

RevGTO

iTrader: (12)

At 125 your tranny is not even up to operating temp; for instance, lock-up occurs at 140-150. The fluid is not able to do its job optimally if it's too cool also. Perhaps one benefit of running the fluid through the radiator is getting it up to operating temp quickly. Everyone knows that too much heat destroys trannys, but that doesn't mean that "cooler is always better."

GregWS6&z28

iTrader: (8)

you're saying that heat controls lockup???? ummmmmm

then can you tell me why mine locks up fine with temps at 110 degrees?

so what's the trans operational temp?

trying to put all of this together

SeeYaSucker

My converter Locks great at low trans temp fluids. I will bypass the factory cooler on my wifes car and I really do believe it will lower trans temps.

AK's WS6

Mine won't lock up right away when it's cold out, but I don't have a trans temp gauge, so i'm not shure what the actual temp. is.

slowpoke96z28

iTrader: (2)

being grand rapids MI, i'm pretty sure its colder that where SLVRLS1 is.
i kinda look at it like the T/B bypass. it'll work great for 95% of the people, but some places get cold enough to need the coolant to help warm up.

gwj

Normally I run my tranny cooler AFTER the radiator in summer, BEFORE the radiator in winter. I was getting lots of PO751 codes in the winter when the trans oil was taking a while to heat up until doing the "winter" switch. And this is in Florida.
Even running the tranny cooler before the radiator in summer my trans oil temps seldom get above 178*.
I'm not a big fan of high trans temps, but I'm not partial to the oil taking a long time to heat up, either.
my .02.

SeeYaSucker

Yeah, I totally agree with you on the different climates, It rarely gets real cold here, But I did bypass the factory cooler on the wifes car and I did in fact see a 20-25 degree drop in trans temps, just by bypassing it, however it did take a little longer to reach its max temp, but just slightly longer. For people in warmer climates I think its great for lower Trans. temps.

99ssleeper

iTrader: (98)

I have the 24K cooler in conjunction with the stock cooler and my temps stay 150-175 all the time. In cool weather they drop to about 110-120...but my 3500 converter locks up just like normal all the time.

CAT3

iTrader: (9)

Sounds like I'll have to bypass my radiator cooler. I could use the additional cooling, here in Hawaii and when I PCS to Arizona. Good looking out.

RevGTO

iTrader: (12)

Now that I think of it, the sensor may be keyed to coolant temp, not tranny fluid temp. Does anyone know? On my car, it doesn't lock until it's just a hair shy of the first line (160* or whatever it is).

SeeYaSucker

Yeah I am pretty sure its with the coolant temp, B/C my converter won't lock until the engine is warm, but locks at any trans. fluid temp.

SmokingWS6

iTrader: (1)

SLVRZLS1, i have the opposite finding, in the winter I can leave with a cold motor or after warming the motor up for 15 mins but the trans still will not lock untill after a few mins of driving.

I forget the exact trans temp needed for lockup but I believe its around 100*. I had to drive my car once in 5* and it still locked up, it took longer than normal, maybe 5-10 mins of driving before it went into lockup.

FaSS Blac

I'm only gonna say this one more time!! I run two trans coolers, a Derale deep pan, with cooling tubulatores, and Mobil One synthetic fluid. I also tried the radiator/bypass experiment and went back to the bypassed setup because the temps were way to high going through the rad. I had a torque converter unlock problem on the highway that made me hook the rad back in the system. This did not help. LSS, it turned out to be my Hypertech 160 T-stat was making the engine run to cold on the highway, (170-172 then unlock). Put the stock 195 back in, problem solved. I then bypassed the rad and tested again. No problemo. The engine temp has more to do with trans function than people realize. My car also runs leaner with the 195 stat and that "silly" SLP y-pipe. It feels +20 hp up on it's game now with the two. I talked to a 12 year veteran of 700R rebuilds last night, and he confirmed everything I've been doing as good for the trans longevity. He had to fight tooth and nail a few years back, to convince his penny pinching boss to go synthetic in the fleet trucks they had. He finally convinced them that they would actually save money because they would not have to change fluid near as often. He also put the largest Hayden type coolers on the trucks too. He confirmed the -25 degree temp thing was not a myth either. My trans stays at a hair above 100 degs in the winter on the way to work, but locks the converter everytime, once the ENGINE reaches 177 degs. Oh BTW, my trans shifts a lot firmer with the stock 195 t-stat in!!!!

SmokingWS6

iTrader: (1)

My converter will lock long before the ETC reaches 170*

Did your raise or your disable your misfire counts? Odds are you were having an excessive amount of missfires, more so with your 160* tstat and it was causing your converter to unlock. I raised all my missfire counts and have never had a locking issue since.

Also, why the heck would you run a 195* stat when the stock is 180
If your doing this to force the converter to lock and get 'better milage, you need to ditch the hypercrap ect and buy hptuners

FaSS Blac

The stock T-stat is 195. I lock up at high 17x's in the winter when it's really cold. I've never had a missfire code.

SteveC

I respectfully disagree with this statement. I have a Y3000 2.0STR, with a 24k B&M cooler, and a 3qt deeper B&M pan. Normal freeway driving, I am running anywhere from 120F to 135F, and I achieve full lockup @ 43MPH.

SteveC