Notices
 
 

  

User Tag List

Thread: A6 3.0 TDI - sudden smoke & oil loss

Page 1 of 3 123 LastLast
Results 1 to 10 of 21
  1. A6 3.0 TDI - sudden smoke & oil loss 
    #1
    Join Date
    Dec 2015
    Location
    UK
    Posts
    91
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    A6 3.0 TDI - sudden smoke & oil loss

    Driving along then suddenly clouds of grey/white/blue smoke. Crawled a few miles home, smoke much less off load. Within ten miles, low oil warning.
    Car has had history of periodic blue smoke 'bombs' (usually only after unusual attitudes eg multi-storeys etc), so a few months ago I vented the CCV
    to atmosphere (via a filter) and the blue smoke 'bombs' completely stopped. Was planning a catch can, but was proving difficult. Now this.

    Nothing on VCDS.
    No lights on dash.
    No rough running.
    Idles normally with no smoke.
    No smoke on start up or when cold.
    No change in power.
    Starts and drives normally.

    Suspected turbo. No damage to compressor. Clean, with a little fresh oil at intake, but normal 2-3mm radial end float and not touching casing.
    Axially, normal play guessing about 0.1-0.2mm. Spins freely. Spindle not broken.
    Turbine, no damage. Same axial play, but radial end float barely detectable. Matt black apearance. No visible oil.
    Actuator freely operates throughout range.

    Charge air from turbo, found a little fresh golden oil (just been seviced) . Enough to dribble one end to the other, but pipe clean other than that.
    I'm not convinced it's turbo.

    CCV/PCV? Tried a surgical glove at idle, barely half inflates. However I havent (yet) tried that at normal RPMs. I can see a little oil collected at the
    bottom of the 'V', right near the CCV, which could be suggestive of it being blocked/high crankcase pressure.
    I sucked on this CCV pipe from the air inlet end and it was definately blocked solid. YET, when the engine is running smoke oil is seen.
    Is my suck too little and proves nothing, or does this suggest high crankcase pressure to open the valve?

    Wonderful car, hard to find now with rare high spec and still with sensible miles, but I'm tempted to throw it in the river!

    Any ideas please?
    A6, C6, ‘55, BMK, S-line, 4F5, 7GN, Sunroof, Bose, Xenons, LEDs, Valcona, Pearlescent
     
    0 0 0
     

  2. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #2
    Join Date
    Jan 2007
    Location
    Nottingham, England
    Posts
    42,107
    Post Thanks / Like
    Blog Entries
    4
    Mentioned
    108 Post(s)
    Tagged
    1 Thread(s)
    Quoted
    1816 Post(s)
    Sounds like injectors diluting the oil which then pulses into the intake system and engine, it can cause runaway which is bloody scary...
    Anthropogenic climate change, the biggest con inflicted on mankind since religion...

    Slava Ukraini
    !


     
    0 0 0
     

  3. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #3
    Join Date
    Dec 2015
    Location
    UK
    Posts
    91
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    Thanks, Crasher. I wondered same initially, but there is/was no diesel smell to the old/new oil (also still thick consistency), and VCDS show all injectors within sensible individual and group (each bank) limits. Plus, why would that manifest suddenly?
    Scary yes, but I dont have a choice right now, to not runaway (pun intended ), but to try and figure this out. This didnt build up over time (I dont think), something 'blew' within 100 yards.
    Could the CCV have suddenly blocked, causing over pressure up the turbo oil drain pipe, enough to push oil out the compressor side seal? It is the most worn, by radial play?
    So few clues, where do I start?
    A6, C6, ‘55, BMK, S-line, 4F5, 7GN, Sunroof, Bose, Xenons, LEDs, Valcona, Pearlescent
     
    0 0 0
     

  4. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #4
    Join Date
    Jan 2007
    Location
    Nottingham, England
    Posts
    42,107
    Post Thanks / Like
    Blog Entries
    4
    Mentioned
    108 Post(s)
    Tagged
    1 Thread(s)
    Quoted
    1816 Post(s)
    Well the compressor doesn't actually have a seal as such, it is termed as a "piston ring" which is odd but true and if crankcase pressure is too high this can be overwhelmed and dump oil in the charge air system and even cause the shaft to break as we saw happen on an S6 V8T late last year when the drain back screen became blocked and the shaft snapped, then the turbine wheel off the right bank fell out into the cat and then filled the exhaust from turbo to tailpipe with the entire contents of the sump!
    Anthropogenic climate change, the biggest con inflicted on mankind since religion...

    Slava Ukraini
    !


     
    0 0 0
     

  5. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #5
    Join Date
    Dec 2015
    Location
    UK
    Posts
    91
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    Ouch! I hope that's not that loverly blue one near Oxford I have had my beady eye on in AT...

    Did the spindle snap due to oil burning erosion at the piston? How did you prove the overpressure, to correct the underlying cause?

    This does perhaps appear to broadly fit my scenario. Since my turbo is already off, despite no obvious external sign anything is amiss with it, I wonder whether a quick internal check is a prudent next step?
    Then, check turbo drain pipe clear, refit turbo and somehow rule in/out overpressure. Suck out any charge air/IC pipework oil before starting, then try to determine if CCV diaphragm is blocked (surgical glove above idle rpm). Any other way to test this?
    The only other culprit I can think of is excessive blowby (compression tests), but the motor is/was strong, no missing and never used a drop between services.
    Can you think of anything else? Does that sound a sensible plan to you? I really appreciate your help.

    This is the third major smoking issue in four years (the first two I managed to solve myself), so this might become my first and LAST diesel.

    "What sanity knows we need, is an odorless and noiseless staid little electric brougham". Oh, how true!
    A6, C6, ‘55, BMK, S-line, 4F5, 7GN, Sunroof, Bose, Xenons, LEDs, Valcona, Pearlescent
     
    0 0 0
     

  6. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #6
    Join Date
    Jan 2007
    Location
    Nottingham, England
    Posts
    42,107
    Post Thanks / Like
    Blog Entries
    4
    Mentioned
    108 Post(s)
    Tagged
    1 Thread(s)
    Quoted
    1816 Post(s)
    Well that car now has tow shiny new genuine turbos and the owner about £7K lighter of pocket, damn things are not repairable or available from anyone aftermarket. When we called TPS I asked them to check UK stock and Dorden had dozens of paris of them and at £5k a pair you don't kep that many for a very uncommon engine unless there is an "issue" When buying the new huffers ETKA says to also order another part, this is the return filter screen. When we took it apart, the screen was blocked and the new one made of a coarser material... I will leave that one ti your imagination but yes, it is a known issue and no, I is black. For some stupid reason I can't find my pictures of the new ones fitted., they looked sexy.... I like the sticker on the intercooler, basically it says if you drive with the engine cover off, you will set fire to the bonnet...



    Anthropogenic climate change, the biggest con inflicted on mankind since religion...

    Slava Ukraini
    !


     
    0 0 0
     

  7. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #7
    Join Date
    Dec 2015
    Location
    UK
    Posts
    91
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    That's a pity, I thought the S6 C7 was something of a (relative) reliability gem.
    That's the second time I've heard of such expensive issues on it.
    I assume the RS is the same risk with the hot vee twins?
    German sticker humour, you know .

    Thanks again Crasher, no mesh on mine, but I’ll pay particular attention to the that drain.
    Last edited by 'WG'; 11-05-2019 at 10:51 AM.
    A6, C6, ‘55, BMK, S-line, 4F5, 7GN, Sunroof, Bose, Xenons, LEDs, Valcona, Pearlescent
     
    0 0 0
     

  8. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #8
    Join Date
    May 2012
    Location
    Everywhere
    Posts
    2,941
    Post Thanks / Like
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    308 Post(s)
     
    0 0 0
     

  9. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #9
    Join Date
    Dec 2015
    Location
    UK
    Posts
    91
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    Noted, thanks
    A6, C6, ‘55, BMK, S-line, 4F5, 7GN, Sunroof, Bose, Xenons, LEDs, Valcona, Pearlescent
     
    0 0 0
     

  10. Re: A6 3.0 TDI - sudden smoke & oil loss 
    #10
    Join Date
    Dec 2015
    Location
    UK
    Posts
    91
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    Turbo passed inspection. Drain is clear, no screen, and no crud.
    Crankcase ventilation valve and pipe to it, looks like new. No crud in pipe.
    CCV blows freely from both ends, which is really weird, as when it situ it was completely blocked when suck/blow from intake end.
    Only sign anything wrong in the V is some water!
    How could this cause smoke and oil loss?
    Can anyone connect the dots?
    What a mare.
    A6, C6, ‘55, BMK, S-line, 4F5, 7GN, Sunroof, Bose, Xenons, LEDs, Valcona, Pearlescent
     
    0 0 0
     

Page 1 of 3 123 LastLast

Similar Threads

  1. Mk5 2.0 gt tdi 140 - sudden power loss ?
    By FrenchToGerman in forum Golf MK5 - 2004 - 2009
    Replies: 5
    Last Post: 27-02-2018, 07:24 AM
  2. Question A3 sudden loss of oil
    By Rupie in forum Audi A3 - 8P - 2004 - 2012
    Replies: 0
    Last Post: 08-06-2013, 05:48 PM
  3. A6 Allroad 2.5 TDI Sudden loss of drive and oil loss
    By Nev.d.y in forum Audi A6 - C5 Forum - 1998 - 2004
    Replies: 14
    Last Post: 12-03-2011, 10:03 PM
  4. Please Help Smoke and sudden powerloss under load at speed??
    By kaipassat in forum Passat - B5 Forum - 1997 -2005
    Replies: 8
    Last Post: 14-04-2009, 03:38 PM
  5. '99 Passat 110 TDI - Sudden Power loss with Black smoke - HELP!
    By new2vwa in forum Passat - B5 Forum - 1997 -2005
    Replies: 4
    Last Post: 11-08-2008, 10:19 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


 



  


Disclaimer: VW Audi Forum is an "independant enthusiast website", administered in line with guidelines supplied by VAG in the UK, and is in no way related to any of the Worldwide Volkswagen,Audi,Seat,Skoda,Bentley,Bugatti,Porsche or Lamborghini group of Companies. For official up to date information on any of there vehicles, please visit the official websites. Any comments made throughout this website, are the views of the respective poster, and in no way represent the views of the VW Audi Forum Administration, or the worldwide Volkswagen & Audi Group of companies.


VW Audi Forum do not vet and are not responsible for any information which is posted in this forum. All content is viewed and used by you at your own risk and we do not warrant the accuracy or reliability of any of the information.


Copyright: Certain "words", "phrases" and "Images" used on this website by the Administration are "Copyright" of Volkswagen GB, Volkswagen AG (Germany), Audi GB, Audi AG (Germany), Volkswagen Motorsport GB, Volkswagen Motorsport AG (Germany), Audi Motorsport AG (Germany), Volkswagen Racing GB, Bentley, Bugatti, Porsche and Lamborghini. No image can be replicated by anyone WITHOUT the relevant Companies written permission.


All trademarks and copyrights remain property of their respective owners.

No part of the VW Audi Forum website or forum may be reproduced without written permission from the site administration


PLEASE NOTE - PERSONAL ABUSE, ABUSE AGAINST THIS OR ANY OTHER WEBSITE OR ANY COMPANY WILL NOT BE TOLERATED. OFFENDERS WILL BE MODERATED OR EVEN BANNED.


This website and forum are best viewed at a minimum resolution of 1024 by 768.



  



- VW AUDI Forum - The #1 Volkswagen (VW) Group Forum - Volkswagen (VW) - Audi - Seat - Skoda - Bentley - Bugatti - Lamborghini - Porsche - Scania - MAN - Ducatti - VW Audi Forum -


- www.vwaudiforum.co.uk - www.vwaudiforum.co.uk -