I bought a 2001 A6 2 months ago with 51k miles on it. A week ago I got check engine light and I was told it was a problem with the transmission. One0 transmission specialist told me that at highway speed the torque converter slips and should be replaced; he said it could also mean that it had shattered and damaged the entire transmission and it should be rebuilt
I took it to another mechanic for a second opinion. They said that the same problem could be electric, caused by any part of the circuit, like the solenoid. They reset the light and said it might not come back up, and if it did, they'd first open the pan and just check the circuitry.
I don't know which one to accept, but the second mechanic sounds more trustworthy; even though he charged double the amount of the first one for the diagnosis, but didn't look like someone who wanted to rip me off. On the other hand I'm afraid not taking care of the problem and driving it in this condition leads to the worst case scenario, the torque converter shatter and damage the entire transmission. Any ideas? I hear the problem with the torque converter is common, especially with the seal, but at what mileages?!

 

I have the same problem with my girlfriend's car. I've been preparing for a torque converter replacement.

BMW's and any other manufacturer who uses the 5HP19 transmission has the same problem. 15+ years ago, someone at ZF decided to use a $1 o-ring in the torque converter instead of a $3 o-ring. It made sense for them because when you build 10 million units, saving $2 a unit adds up.

For us this means that the o-ring fails during the vehicle's expected service life.

The transmission control software detects that the converter clutch is slipping and disables the converter clutch in software.
This means that once the computer detects that the clutch has failed, it STOPS TRYING TO APPLY IT.
This means that the problem WILL *NOT* GET WORSE. It is OK to wait.

Reman torque converters can be had for as little as $300 + core. Of course, Audi's book labor for torque converter R&R is something like 11 hours...

 

Thanks very much. So I shouldn't buy into the idea that the converter shatters through the transmission and there's a possible need for rebuild. I'll wait until the light comes back up and then take care of it.

Thanks again!

 

My girlfriend's car has had that code set for over a year.
Either the PO or dealership had taped over the CEL to hide the fact that it was throwing a code, so it could have been longer than that.

I have not noticed any degradation of transmission function during that period.

There are some older transmissions for which a failure of the converter clutch can require a transmission rebuild... for example the Chrysler/AMC Torqueflite 998/999 can do that. It's vulnerable because the converter clutch is hydraulically controlled in addition to being hydraulically actuated. That means that there's no feedback to disable a failed converter clutch.

The electronics controlling the ZF transmission are smart enough to protect it from that particular failure mode.