Torque Converter on RS6

Started by Q_Cars, July 03, 2010, 05:48:11 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Q_Cars

Bugger bugger bugger.

Guess what the first error was that popped up when I first plugged in my newly acquired VAG-COM.....17125 - Torque Converter Clutch: Stuck OFF / No Power being transferred. The diagnosis is that the lock-up clutch is not engaging properly, and sticking open.

The TC clutch works fine with gentle driving, but hard throttle application sees the clutch slip, and when it doesn't engage properly, the TCU will signal the clutch to remain in the open position (this is a fail-safe mode I think, which stops the clutch from burning out, which then fills the ATF with clutch material which distributes itself through the rest of the transmission, which ultimately leads to tranny failure as well).

There's quite a bit of info on this available on RS6.com and RS246.com. It appears that with the ZF5HP24 tranny there is an internal oil seal in the torque converter that fails, meaning the control valve for the clutch doesn't hold sufficient pressure to close the clutch. I did some logging with the VAG-COM:

Here's normal operation on gently pulling off from stop to about 90 kph  (truncated the log file to save space):


You can see the signal status from the TCU to the torque converter change from open to regulating to closed, and the engine revs are matched by the transmission input revs showing the clutch has locked up.

Here's what the situation looks like after doing a hard launch and then settling to constant speed:


The TCU has now signalled the clutch to remain open when it detected slippage, and engine revs are higher than the transmission input revs (which comes through the slip in the viscous coupling in the torque converter). On the road at a constant 100 kph I can tell whether the clutch is closed (revs are 2050) or open (revs are about 2200).

It's off to CCS to get an assessment, but unfortunately it is an engine out job to do the torque converter in an RS6 - 20+ hours of labour alone. I've got a mechanical warranty, but that will likely mean a reconditioned rather than new torque converter (and I hope they put the revised seal in!). I'll probably get them to do some of the other items that need an engine out job to get to (one of the valve cover gaskets, EGTs and O2 sensors). I'm a bit nervous about this one, because there has been commentary on other forums that a torque converter replacement has been followed by transmission failure for a few cars  :( :( :(

The RS6 is a bloody awesome car, but these sorts of things do test your loyalty I must say!



-----------------------------------------------------------
2007 Mk V GTi (Owned by the Speaker of the House)
1998 Alfa 156 2.0 T/spark (to satisfy petrosexual urges)
2005 Holden Monaro Stage 4 (made of pure boganite)
2006 BMW K1200R (aka Herman Munster)
2006 E63 AMG (sold, phew!)
2003 C5 RS6 (sold, sadly)

beeker

Phew for the wty.
Lets hope you dont exceed your insurance warranty maximum claim.
14 RS6 Avant Black
23 RS6 Performance avant on order
17 Q7 S Line 200kw
93 E36 M3 Targa Car
01 Porsche Boxster Series Race Car
17 Porsche 991.2 GT3 clubsport
94 DC2 Integra Targa/Track Race Car
13 TR86 race car
2018 Highlander
2017 Outback

Q_Cars

Quote from: beeker on July 03, 2010, 06:41:23 PM
Phew for the wty.
Lets hope you dont exceed your insurance warranty maximum claim.

+1 on that. The warranty has had a fair old work out over the last year or so: thermostat replacement (requires effectively same procedure as cambelt change to get at it, so 7 hrs labour charge!), two transmission oil leaks, auxiliary coolant pump (another 8 hrs labour) and now this. I've got the AA mechanical warranty which interestingly excludes M-series BMWs and AMG-series Mercs, but no mention of RS-Audis. I suspect my car will cause them to change that :-\
-----------------------------------------------------------
2007 Mk V GTi (Owned by the Speaker of the House)
1998 Alfa 156 2.0 T/spark (to satisfy petrosexual urges)
2005 Holden Monaro Stage 4 (made of pure boganite)
2006 BMW K1200R (aka Herman Munster)
2006 E63 AMG (sold, phew!)
2003 C5 RS6 (sold, sadly)

Q_Cars

Quote from: Q_Cars on July 06, 2010, 08:29:36 AM
+1 on that. The warranty has had a fair old work out over the last year or so: thermostat replacement (requires effectively same procedure as cambelt change to get at it, so 7 hrs labour charge!), two transmission oil leaks, auxiliary coolant pump (another 8 hrs labour) and now this. I've got the AA mechanical warranty which interestingly excludes M-series BMWs and AMG-series Mercs, but no mention of RS-Audis. I suspect my car will cause them to change that :-\

Maybe Santa does exist after all....CCS had the car yesterday to do the diagnostics on the torque converter (and the 17537 code on banks 1 & 2, "fuel trim: system too rich" that also came up as an error code). What they found was that the ATF level was low (down by 2L). They topped it up, reset codes, gave it a damn good thrashing and not only has the torque converter code gone, but the fuel trim code too. Touch wood, it was low ATF all along. Clearly this was causing hydraulic pressure problems in the torque converter and the box (which I noticed has flared and clunked a wee bit more than normal over the past few months). I'll monitor it for the next couple of weeks, but it's looking good.

Of course, that begs the question, where did 2L of ATF go? Well 2 services ago CCS fixed a leaking seal in the transmission. They wouldn't cop to it, but my guess is (not that I could ever prove it) that they did the seal and didn't check the ATF level at the time. I'm also a wee bit annoyed that when I reported the TC error code 17125 to them when I had it serviced 1,000 km ago, they just reset the code and told me to monitor it, rather than dig deeper. I've been really pleased with CCS up until now, but I think they dropped the ball a bit with this one (although we got there in the end).

Anyhow, last night on the run home between Albany and Silverdale at 9pm, with an ambient temp of 2C and a properly functioning transmission, my RS6  found its mojo again. The engine felt crisper (since it was not running too rich), the changes were crisper, and the TC locked up properly again instead of spinning all the energy away into the ATF. All is right with the world ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D
-----------------------------------------------------------
2007 Mk V GTi (Owned by the Speaker of the House)
1998 Alfa 156 2.0 T/spark (to satisfy petrosexual urges)
2005 Holden Monaro Stage 4 (made of pure boganite)
2006 BMW K1200R (aka Herman Munster)
2006 E63 AMG (sold, phew!)
2003 C5 RS6 (sold, sadly)

beeker

Quote from: Q_Cars on July 10, 2010, 08:56:23 AM
Maybe Santa does exist after all....CCS had the car yesterday to do the diagnostics on the torque converter (and the 17537 code on banks 1 & 2, "fuel trim: system too rich" that also came up as an error code). What they found was that the ATF level was low (down by 2L). They topped it up, reset codes, gave it a damn good thrashing and not only has the torque converter code gone, but the fuel trim code too. Touch wood, it was low ATF all along. Clearly this was causing hydraulic pressure problems in the torque converter and the box (which I noticed has flared and clunked a wee bit more than normal over the past few months). I'll monitor it for the next couple of weeks, but it's looking good.

Of course, that begs the question, where did 2L of ATF go? Well 2 services ago CCS fixed a leaking seal in the transmission. They wouldn't cop to it, but my guess is (not that I could ever prove it) that they did the seal and didn't check the ATF level at the time. I'm also a wee bit annoyed that when I reported the TC error code 17125 to them when I had it serviced 1,000 km ago, they just reset the code and told me to monitor it, rather than dig deeper. I've been really pleased with CCS up until now, but I think they dropped the ball a bit with this one (although we got there in the end).

Anyhow, last night on the run home between Albany and Silverdale at 9pm, with an ambient temp of 2C and a properly functioning transmission, my RS6  found its mojo again. The engine felt crisper (since it was not running too rich), the changes were crisper, and the TC locked up properly again instead of spinning all the energy away into the ATF. All is right with the world ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D


You lucky man!
14 RS6 Avant Black
23 RS6 Performance avant on order
17 Q7 S Line 200kw
93 E36 M3 Targa Car
01 Porsche Boxster Series Race Car
17 Porsche 991.2 GT3 clubsport
94 DC2 Integra Targa/Track Race Car
13 TR86 race car
2018 Highlander
2017 Outback

Q_Cars

Quote from: beeker on July 10, 2010, 09:07:31 AM

You lucky man!

I spoke too soon  :'( The fault code came back, and CCS has confirmed the torque converter fault is real, and replacement is required.

However I have also taken the opportunity to take stock, and the RS6 has cost NZ$25,000 in service and repairs (some covered by warranty) over the past 15 months. It's not so much the cash (I went into this car with my eyes open), it's the time I haven't been able to use it. The car has been at CCS every week for the past month for various misdemeanors, including power steering fluid leak, hazard switch and indicator stalk contact failures, tranny (as per thread) and in the past two months has suffered auxiliary coolant pump failure and two other transmission leaks.

Enough is enough. I love driving the beast but it became too hard to own at 155,000 km, especially as a daily driver (I seriously considered keeping it for a Sunday driver...).

Sorry to say, I've jumped ship from the Audi fraternity (still got the Mk V GTi tho)....I've traded the RS6 on a mint 2007 Merc E63 AMG with 50,000 km on board and an absolutely loaded warranty that I hope I won't need for a while. I guess 380 kW is a partial compensation for the biturbo boost  :laugh:

I will absolutely miss driving the RS6, but the E63 has already shown that it can make me giggle uncontrollably especially when I turn the ESP off (I told my significant other that ESP stood for Extra Smoke Program....from the tyres that is  >:D   ).
-----------------------------------------------------------
2007 Mk V GTi (Owned by the Speaker of the House)
1998 Alfa 156 2.0 T/spark (to satisfy petrosexual urges)
2005 Holden Monaro Stage 4 (made of pure boganite)
2006 BMW K1200R (aka Herman Munster)
2006 E63 AMG (sold, phew!)
2003 C5 RS6 (sold, sadly)

beeker

Quote from: Q_Cars on July 26, 2010, 08:07:10 PM
I spoke too soon  :'( The fault code came back, and CCS has confirmed the torque converter fault is real, and replacement is required.

However I have also taken the opportunity to take stock, and the RS6 has cost NZ$25,000 in service and repairs (some covered by warranty) over the past 15 months. It's not so much the cash (I went into this car with my eyes open), it's the time I haven't been able to use it. The car has been at CCS every week for the past month for various misdemeanors, including power steering fluid leak, hazard switch and indicator stalk contact failures, tranny (as per thread) and in the past two months has suffered auxiliary coolant pump failure and two other transmission leaks.

Enough is enough. I love driving the beast but it became too hard to own at 155,000 km, especially as a daily driver (I seriously considered keeping it for a Sunday driver...).

Sorry to say, I've jumped ship from the Audi fraternity (still got the Mk V GTi tho)....I've traded the RS6 on a mint 2007 Merc E63 AMG with 50,000 km on board and an absolutely loaded warranty that I hope I won't need for a while. I guess 380 kW is a partial compensation for the biturbo boost  :laugh:

I will absolutely miss driving the RS6, but the E63 has already shown that it can make me giggle uncontrollably especially when I turn the ESP off (I told my significant other that ESP stood for Extra Smoke Program....from the tyres that is  >:D   ).

Ouch, thats allot fo bad luck. Have fun with the E63.
14 RS6 Avant Black
23 RS6 Performance avant on order
17 Q7 S Line 200kw
93 E36 M3 Targa Car
01 Porsche Boxster Series Race Car
17 Porsche 991.2 GT3 clubsport
94 DC2 Integra Targa/Track Race Car
13 TR86 race car
2018 Highlander
2017 Outback