V10 question: sticking turbo - safe to leave alone?

da.hs

Veteran Member
Joined
Jul 28, 2012
Location
SK, Canada
TDI
2010 Golf, DSG, silver (from new). 2010 Audi Q7 (from 2016), 2004 Touareg V10 (from 2018)
A 2004 V10 with a nice colour scheme: the seller states all good except "There is an issue with the left turbo variable vanes being sticky at times, thus not producing full power. Backing off the throttle, then re-applying seems to cure this and full power is restored."


The problem as described doesn't sound too bad, I would leave until there are other reasons for an engine-out maintenance - but is it a sign of imminent complete turbo failure that would spit oil everywhere and cause major damage?


I haven't yet looked at the car. It's quite a distance away.
 

Fourdiesel

Veteran Member
Joined
May 19, 2003
Location
SW Wash. USA
TDI
'04 Touareg V10 TDI
IF (emphasis intentional) sticking turbo vanes are the issue, good 'Italian Tune' might clear it up. ie, find a good LONG hill - such as a mountain pass - with several miles of decent uphill grade and not too much traffic, drive up that hill and push the engine hard. You needn't floor it but the object is to get the exhaust really hot to the point of burning off most of the carbon gunk that forms on the vanes - 10 minutes or longer. Get it hot, keep it hot.

However, that may not be the issue because it is hard to envision a circumstance where the sticking of only one set of turbo vanes and the other turbo operating normally wouldn't set a check engine light because of that pressure imbalance.
But the Italian Tune is an easy fix if it works - and expensive if something breaks.
 

kooyajerms

grocery getter
Joined
May 5, 2004
Location
Pomona, Southern California
TDI
97 B4V (mine), 11 x5 35d (hers) 04 V10 (that one you want), 2014 Q7 (mom's) 74 Shasta 1400
What’s the price before we determine if it’s worth it to buy. Assume the worst and see if you are ok with that price. If you are, you can troubleshoot a couple things that cost less.

I’ve had control module issues with my vanes since last year, but I can drive it with full power with a bit of Voodoo magic.
 

Matt-98AHU

Loose Nut Behind the Wheel Vendor
Joined
Apr 23, 2006
Location
Vallejo, CA
TDI
2014 Passat SE DSG, 2005 Passat wagon, 2004 Touareg V10.
Vane sticking can cause these to throw a "turbo control module defective" code, even though the module is actually perfectly fine. And that code is effectively instant limp mode before you've even put it under load.

You can drive it, it just won't be very impressive.
 

kooyajerms

grocery getter
Joined
May 5, 2004
Location
Pomona, Southern California
TDI
97 B4V (mine), 11 x5 35d (hers) 04 V10 (that one you want), 2014 Q7 (mom's) 74 Shasta 1400
I had that module rebuilt 3 times and the other one that temporaptor purchased rebuilt too. Tried so hard to Italian tune up the thing into submission but it never worked.

I tried a couple different methods of clearing that code. You can’t use one of those cheap code readers, or it would hard reset. I pretty much clear it anytime I get off a stop light. Not my favorite task, but it does let me run both turbos out of that dreaded limp mode .
 

Matt-98AHU

Loose Nut Behind the Wheel Vendor
Joined
Apr 23, 2006
Location
Vallejo, CA
TDI
2014 Passat SE DSG, 2005 Passat wagon, 2004 Touareg V10.
I do remember running basic setting 11 in both modules on your V10, Jeremy, and I do seem to recall one bank always slightly lower pressure than the other. It might be that the one bank is sticking and not *quite* reaching the max position, it's setting the control module code because it knows it's not moving to its full extent, but the problem is sticking in the turbo, not that the control module itself is at fault.

Sticking vanes are unfortunately difficult to fix, especially on one of these with how difficult access is and the odd layout. Hell, even on an ALH I stopped trying to free up sticking vanes for people and just say buy a new turbo. After a couple people came back with overboost codes on those cars weeks after, I had to. New Genuine Garrett or Borg Warner for them or nothing is all I recommend anymore if we're to guarantee it will be a long-lived fix.

Sadly, easier said than done on a V10! I do have a pair of used turbos I'll be cleaning up and putting on Jason's former beast while I'm in there doing cams. Take apart the old one with sticking vanes and see if the vane mechanism itself is from an easier to find turbo.

Of course if you have to pay someone the labor to remove the engine to get at the turbos, you might as well put new turbos on there so you don't have to do the job over again.

And the case of sticking vanes on Jason's former V10 were likely exacerbated by the badly worn cam on bank 2...

These babies aren't cheap to upkeep and fix, that's for sure.
 

da.hs

Veteran Member
Joined
Jul 28, 2012
Location
SK, Canada
TDI
2010 Golf, DSG, silver (from new). 2010 Audi Q7 (from 2016), 2004 Touareg V10 (from 2018)
Well, I ended up buying it.. 1700km over mountain highways to get home and runs beautifully. Yes I understand it's not an economical daily drive! No codes so far.
 
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