Hi, Sorry for the long post, but there is good news towards the bottom. If you're just here for the blobs, please help me ID what that is in the filter below.

Background: I just went through a few weeks of freaking out because I had the dreaded P0741 - 17125 codes. Today they stopped showing up. Here's what happened for those interested:

I purchased the vehicle ('02 Audi A6 Avant) in September '12. In October I replaced all the fluids and filters because I did not know the state of any of them.

In early December the CEL came on with codes P0741 - 17125. At some point shortly before that the car went into limp mode. Limp mode came on with starting the car. I drove it for a few minutes because I had no idea what limp mode was. Then I shut off the car, turned the car back on and limp mode has never returned.

However, I feared the worst with the P0741 - 17125 codes. Because some said the codes, and behavior (the torque converter was actually sticking open sometimes), could be caused by low transmission fluid, I ensured it was filled per the ZF instructions again. It was, so the fluid level was not the problem.

The TC continued to get stuck open so I was resigned to spending the money to replace it. But then I read that gunk can get loosened with new ATF, which may clog the filter. And I started doubting the Redline D4 I put in it (supposed to be compatible and to spec).

Yesterday I changed the ATF and filter again, trying to get as much Redline D4 out as possible. This time I put Ravenol 5/4 HP ATF in. Driving round trip to work and back always produced the P0741 - 17125 since those codes started appearing. This time the codes did not appear and VCDS reported the TC operating as expected.

During the ATF change I inspected the pan, magnets, and filter. The pan and magnets were normal (no metal, no particles of any size, just a very light amount of sludge). However, in the filter there was a 1/4" clear gelatinous blob, around eight or so black particles, and one almost microscopic piece of aluminum. There were actually two blobs. I picked out the smaller one and it disintegrated when I lightly rubbed it between my fingers. What would these things be? I'm guessing the black particles are clutch material, not necessarily pieces of the TC seals.

Here are pictures of what I'm talking about.

In this picture above you can see the gelatinous blob.

In this picture above you can see the black particles in the upper right area. The other, smaller blob is also there.

Note: the Redline D4 is red colored fluid.

So can anyone tell me what I might be dealing with in the filter? Thanks!

Recommendations for those who want to change their ATF:
1. Don't.
2. If you ignore #1, only use the ZF or Audi branded ATF with the LT 71141 spec. ZF Lifeguard 5 is the correct product sold for a reasonable price here in the States. It is actually manufactured by Pentosin. The ZF and Audi ATF are semi-synthetic. All the other stuff that is "compatible" is fully synthetic.
3. Get a rubber gasket... so much easier to use than the paper one.
4. Use a hand pump like in the Blauparts kit.
5. Level the transmission using the edge of the pan all the way around.
6. Follow the ZF instructions precisely. It will take a LONG time for the transmission to cool back down.

I'll post another update in a week to let you all know if the ATF really was the issue causing TC to stick open.

Regards,
Tom

 

Just to share my experience, my first fluid change was done using Pentosin. Never had an issue for the 30K miles of use. My second change was done using Redline D4. Never had an issue for the next 30K miles of use.

Redlind D4 meets the Esso LT71141 spec.

A slight correction requested... the although the Pentosin brand is on the ZF approved list, it is NOT confirmed to be ZF factory fluid. ZF factory fluid standard is ESSO LT71141 fluid which is listed to be ZF Lifeguard 5 fluid.

 

I was only stating that the ZF fluid, which is recommended on the ZF specs for the transmission, is supposedly made by Pentosin and is quite a bit cheaper than brand name Pentosin and the dealer stuff. http://www.worldpac.com/tagged/ATF_-_ZF_Lifeguard_5.pdf

Now can anyone tell me what the translucent blob is? I am not a chemist, so I'm only guessing it's the result of the Redline D4 and the factory fluid being incompatible.

 

The TC failed to lock up today this morning. It ran perfectly on Monday, Tuesday, Wednesday and this afternoon. I called Redline and they have no idea what the blob may be or why the TC would work after a fluid change. Can anyone here help me with these two questions?

A. Is the TC bad? If it's bad, why would changing the fluid make it work for three days?
B. Anyone know what that blob may be?

 

TC's are known to go bad in these cars.

sound like you had an issue, I have never seen that crap in the pan before it may have been in the pump that was used to install the fluid or something like that. I only use pentosin.

Their really isn't anything in an auto trans that would produce that jelly.
but it is so thick i can't imagine it made it through the filter, the question also could be is it a chemical reaction between the redline and the original fluid??? you know you can never get it all out because the tc will still be full.

 

Right, but if it worked after an ATF change for three days and there's no significant evidence of TC seal parts in the filter wouldn't that possible point to a working TC?

So if it reacted in the rest of the transmission it could be gummed up in there causing problems with pressure? I'm assuming incorrect fluid pressure could cause all kinds of problems like the TC failing to lock up. Does that make sense to anyone? Can anyone recommend the next course of action?

 

I'm guessing about the reaction. I have never ever seen that before.
I wouldn't think it's in the trany just yet.
treat it as foreign matter that got in via the fluid pump when it was being filled.

If the tc is bad it's bad, doesn't matter why.
I know that's not the answer you want, I wish i could tell you different.

just make sure you use pentosin when you refill, these transmissions don't like just anything. I learned that when i did my first filter change. These transmissions are also a pita to fill correctly.

I put mine on a jack stand warm the fluid with a avg-com connected to monitor the trans temp. with the car running on top of me, Just like the book says and it's still a pita to get it right. But when audi recommends a fluid use that fluid!
and in my opinion better to overfill then underfill it will just blow out the breather if it has to.

 

I would accept that if the TC would stay bad. But it works when the fluid is cold (<50 deg C) and not work when the fluid is hot. Has anyone seen this before?

 

Read this.

www.sonnax.com/system/announcement/85755-08.pdf

it is possible your gum is in the control body.
lots of things are possible.

in order to help you you need to give me;
year and model car.
any codes that you have.
have you inspected the transmission control module?
what was it doing before the fluid and filter change?
what exactly it does now.
how does it shift, hard? normal? slip?
does the engine grumble and vibrate or stall at a stop while in gear?
who did the fluid change and how was the new fluid introduced to the transmission.
was there any issues with the transmission or tc before the fluid change.

Forgive me for asking but how mechanically inclined are you?
do you have the ability to pull the valve body if needed?
it is located under the filter, has wires and solenoids and many bolts.
transmission remains in the car.
you will need tools, and a zf5hp19fla manual from zf.
along with a shift kit and solenoids from ZF.
again that is if you need to go there.

how do you know that the tc is not locking up when it is cold and locking up when it is hot?

my thoughts from the info so far is that it could be possible that this crap was located inside of the filter assy. that is a bad thing. it could be blocking the tcc port or your tcc valve or solenoid could be malfunctioning.

but you should start me from the beginning so i can help you along.

when ever I pull a valve body i install a shift kit and all of the solenoids and always do the updates, which may require drilling out ports to a specific diameter. however a good transmission shop can do this for you as well but they get a ton of dough for it and it really is not such a big job as a rebuild.

 

Ok, here are the answers:

year and model car.
'02 A6 Avant 3.0 Quattro

any codes that you have.
16805 - one of the cats is probably bad
17125

have you inspected the transmission control module?
Nope. What's the procedure?

what was it doing before the fluid and filter change?
The transmission performed normally.

what exactly it does now.
The TCC fails to lock up/gets stuck open when the fluid is hot. This is reported in VCDS and I can feel and see the surge in RPM with no power transfer above 50mph when I tap the gas.

how does it shift, hard? normal? slip?
Shifting is normal. No slip that I can feel. If there is anything I can look for in VCDS to confirm slip, let me know.

does the engine grumble and vibrate or stall at a stop while in gear?
The car has a bit more vibration than I'd like at a stop. When I bought the car I had it inspected and the engine mounts were shot. They were replaced before I bought it. The vibration was reduced, but it's still there. No stalling or stopping while in gear or at a stop.

who did the fluid change and how was the new fluid introduced to the transmission.
I did the ATF and filter change. I followed the ZF procedures. I am confident it was performed correctly because I verified the level twice at the proper temperature and it was correct.

was there any issues with the transmission or tc before the fluid change.
No.

Forgive me for asking but how mechanically inclined are you?
I would say I am above average. I have dropped a manual transmission to change a slave cylinder once. I do all my own repairs.

do you have the ability to pull the valve body if needed?
Yes. It's just unplugging and unscrewing torx bolts, right?

how do you know that the tc is not locking up when it is cold and locking up when it is hot?
VCDS reports the temperature and TCC. I've since heard that someone else with these codes experiences the same. I'm pretty sure the TC is busted.

when ever I pull a valve body i install a shift kit and all of the solenoids and always do the updates, which may require drilling out ports to a specific diameter.
I'm not comfortable with drilling out my VB. I am comfortable replacing components.

Thanks for the help!