So, this has been discussed before, and I've been involved in one or two threads about it, but I have a couple new questions that aren't related to anything I've found yet so here goes.

I have a '13 base A6 with Pfadt headers and a Halltech CAI, along with a 160 tstat. A couple months into these mods, I noticed high transmission temperatures, so I had a B&M transmission cooler installed into the front driver's fender. The factory transmission cooler in the radiator was bypassed (the shop didn't run this by me).

The climate down here (south Louisiana) ranges from ~35 in the winter to >100 on the asphalt in the summer, with very high humidity.

Even with the cooler, my transmission temps will reach 200 after about 45 minutes of driving around town. There's generally some aggressive driving involved, but I'm 20 and that's part of the game. Coolant temps are always below 210, and oil temps seem to peak around 217 or so.

On the racetrack, the transmission temp will easily reach 240, while coolant and oil temps remain stable (don't remember exact levels...)

I feel that these numbers are a bit high, and honestly I'd like to be able to beat on the car as much as I want without worrying about cooking something.

So, my tuner's thrown out a few ideas to try to solve this, and I wanted to get some feedback.

1. Earlier in the year, he suggested that we add another transmission cooler to the other fender. Yeah, this would probably solve the issue but it seems a bit overkill to me...

2. Today, one of the mechanics suggested running 10W40 oil during my next change. Hoping someone who has experience with this will chime in.

3. adding an oil cooler (factory or otherwise) to try to remove extra heat from the engine bay

4. although he previously (a couple months back) said it wasn't worth it, today he suggested that adding a dual fan DeWitts radiator with a TOC run in series with the B&M cooler may be effective

5. use the fog lights as ducts for the transmission coolers. I don't use the fogs much, but I don't want anything looking like crap either. anyone done this?

Now, I'm planning to have the car retuned by Chuck CoW, mostly because my tuner is packed every day of the week from 9AM to 8PM and I don't want to keep going back and forth to get the transmission shifting exactly as I want it to. I'm very happy with the engine tune that I have, and will request that we keep it. I feel like Chuck's tune may help with TF temps and preserve the life of my transmission.

I have plans to add a higher stall torque converter and possibly 3.15 or 3.42 gears this fall, and I eventually have plans to add a head/cam package or forced induction system to the car. Obviously, these mods are going to add significant heat to the entire powertrain, and the torque converter will especially add heat to the transmission, from what I understand. That being said, I want to take care of this issue BEFORE it becomes a $6000 transmission replacement.

This is my only car, so I have to be able to drive it year round...I also want to be able to make it faster without having to baby it to save components from heat.

Opinions/suggestions welcome!

 

Oil temp is spot on. You need 210 to 220 for the additive package in the oil to work.

What kind of oil do you have in the trans? Red Line makes a high temp ATF that would work great in that application.

 

I would get a new cooler like a 12"x12" stacked cooler and put it in front of the radiator independent of the factory cooler, I have a hayden I got at pep boys for around $60 mine takes about 20 miles to get around 160 and hard racing 180 - 195 after the drive there and 5 hot laps also heads cam 3800 converter and 373 gears 4l65 trans, and that's dead center low squeezed between ac condenser and vararam

 

I honestly have no idea. I'll have to look into that. Thanks!
I'm having the DRM Bilstein shocks put on whenever they ship, and I'll also have the engine oil changed at that time. May be a good time to put in higher temp ATF...

I may have to experiment with having my cooler moved there...I will see how the new tune goes, and if temps still aren't in line with where I want them to be I can mess around with it.

 

does the B&M cooler have its own fan?

 

It does. The fan is on anytime the ignition is on (car started or hold the accessory button for 10 seconds.) Wired off of a relay that's turned on with a fuse tap.

The fender well has a number of 3/4" holes drilled in it to allow air to pass through. The airflow in these cars really does suck though. They seem to have figured out quite a few things in my dad's C7A6...will try to take it for a ride tonight to see if temps are any better than mine.

 

It must be to much heat in the engine compartment, if a big enough cooler is put in front of the radiator condenser and your moving at speed it will get cooler air and if your fan comes on sooner it brings more cooler air at idle, I know a few with the a6 trans and converters with bolt/on mods that run real cool with just a 3-4"x 12" cooler mounted under the radiator support and forward frame laying flat so air is forced up the airdam threw it then the radiator

 

Any way to ge a picture of your fan and how you actually mounted it

 

its the stock fan

 

hmm. when I have the car at the shop and on the lift for the shocks, I'll have to take a look at this area to see if I could work something in there. Any idea how that would affect intake temps? I would imagine not much at speed, but still a potential issue.

Is there a particular brand that they go with/where could I find one?

 

Please excuse the double post...

I looked at the Redline ATF and see that there's the D6 made for Dexron VI applications (vettes, etc.), and also one just called high temp ATF, but it doesn't list the Dexron VI as one of its specifications...I need it to be able to run fine on the cold days here (40 F) as well as the hot, which may mean that I'll have to have the shop plumb the trans cooler in the radiator back into the loop. Might have them figure out some sort of thermostat system to get it up to temp fast then just run the auxiliary cooler after 140 or so.
Thoughts?

 

I think this is your problem. I have a similar set-up/mods. I have read in several old threads that you should not bypass the radiator's integrated cooler.
Proper flow is Hot from trans>radiator>B&M cooler>back to transmission.

is there anyway you can try this out before spending any more money?

 

I think I heard my name being called. Actually it's a 6 x 12, but only 3-4" are in the airflow.

I'm currently running to the aux cooler, then into the OEM radiator cooler before going back to the trans. It still runs a little hotter than I'd like in the Phoenix 100-115 temps and so does the engine coolant. I'll get through this summer, but during the winter I'll be installing a second or larger aux cooler and bypassing the radiator and adding an inline 180* t-stat, plus insulating the lines.

It sounds like you don't have enough airflow to the cooler. A bunch of 3/4" holes is nowhere sufficient. That fan is not a big enough help either. I'd just route the cooler return line through the radiator for now, since you'll be doing a higher stall converter soon. You might as well wait on a tune until then too and get yourself in the line for a good dyno tune.

Currently running a 4,000 Yank and it warms up easily in the summer, but a little harder at the track in the winter.

 

Something is off on this setup. Are you sure the fan is working ? Do you have any picture of the intstall ?

I have the B&M cooler with fan installed in front of the front right wheel. The rad is bypassed and the fan is wired to be on whenever the car is running. With 780rwhp, 3.42's, a built trans and stall, I never see over 180 trans temps and rarely that high. Normally they are more like 160 area. I don't run on the track so cant speak to that part but during hard street driving or heavy traffic the temps stay cool. This is with regular GM fluid too.
Assuming the fan is working properly, a few things to check. Make sure the cooler is installed orientated the right way. (the hoses should not be pointing down). I trimmed the air duct under the bumper to flow the air directly on the cooler and put a grill in the fender liner to let the air out. I also rerouted the lines because the factory ones were practically touching the headers and that cant help with heat either.
That cooler should do the job if all is set up right.

 

whats the model # for this cooler?
thanks

 

There's a chance that I can have the mechanic at my tuner do it when I have my DRM shocks put on (whenever they come in). I'll probably go ahead and have them do a fluid swap to some redline synth while I'm at it, so it won't be FREE but close enough I think.

I definitely want to have this done just to maintain a little more heat when I'm on the interstate. Drove about 400 miles Thursday night to my ranch and saw 140 the whole time. I can only imagine how low it'll get during the winter...

Yeah, if you can run those mods in those temps without getting too hot then I definitely have an issue. Can you post a photo of where you have your cooler mounted? might want to invest in one...

The fan on the cooler is on whenever the car is. There's quite a few holes behind the cooler, and the rubber foglight gasket is removed as well. There seems to be a good deal of flow through the holes, but obviously not enough...

The car is already tuned (dyno and street). Engine tune is perfect IMO, trans tune just isn't where I want it and I'm thinking there may be some issues with the converter tables or something that's contributing to the heat issue.

I'll try to get a look at the hose section when I can. I know the fan is facing the same direction. It appears to be the same install that I have, just with everything on the driver side.

What are your ambient summer temperatures/humidity levels?

When you say you trimmed the air duct, do you mean similar to the way that it's trimmed by the factory to flow on the radiator/condenser? any photos?

 

Nice summer days here are around 80 degrees. A really hot day is 90. I believe humidity averages around 70% in the summer.
As for the duct, if you look under the bumper, there is a opening which is a duct. When I installed the cooler the duct was touching it so I had to trim it a little. Rather than just chop it off any way, I trimmed at an angle which directs the air on the cooler. I really don't know how much different that makes.
I don't drive my car in the winter, but did consider that in spring and fall when it is cool, the trans might not warm up enough. One could put a switch for the fan, but I didn't want to bother, so I just put the fuse in a very accessible location under the hood. I can just pull the fuse when temps get cool, and I would thing the cooler without the fan running would keep temps about right.

The cooler is B&M Hi Tek 70298

 

so.....say the hoses ARE pointed down.....

I read the manual for the unit and it sounds like it's just for proper operation of the fan thermostat, and mine isn't even used because the fan is always on. Could the orientation still cause heat issues?

In other thoughts, looking at the B&M website, I'm thinking of adding either a 70255 or 70265 in front of the radiator/condenser, possibly utilizing the inlet from the air dam as an air source. I'd throw the radiator into the loop to heat the transmission up so that I don't suffer during the winter...Thoughts? I figure throwing a couple hundred bucks at this problem now is better than $6500 later...

 

I really don't know for sure if the hoses facing down are a problem, but the instructions specifically show to position then up or on the side. Maybe call their support.and see if they know. Adding another cooler should help, I just think the one you have should do a better job. There must be some reason that it isn't.

Forgot, there is also a specific "in" and "out". May also be just for the thermostat but I wouldn't know that for sure either so I just did it as they said to.

 

Yeah, that's what I'm thinking...maybe the computer decides that the tranny isn't heating up fast enough so it modifies the converter program to build more heat and then by the time it's hot there's just too much heat for the aux cooler to do anything about it? not sure if that's possible.

Alternatively, I'll try to figure out some way to improve airflow to the cooler. I'm inclined to think that the fan really doesn't do enough without a good place to pull air from. No matter how much of a low pressure zone it creates, it still won't flow much unless there's a good intake area. When I get home tonight I'll pull the fender well and see what's what.

Granted, I do live in a warm climate, but if people can keep cammed/stalled cars in the 180 range in temps at or above mine without running multiple aux coolers, I'm inclined to believe that I should be able to keep my nearly stock car around the same range without any issues....I'll send B&M an email and see if they have any advice too.