Notices
 
 

  

User Tag List

Thread: LT35 2.5TDi no power and blue smoke after overrun

Results 1 to 3 of 3
  1. LT35 2.5TDi no power and blue smoke after overrun 
    #1
    Join Date
    Mar 2017
    Location
    Cornwall
    Posts
    2
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    Hi all. First post on here, I can usually get by with my knowledge and from reading other articles, but this time I am really stuck and getting pretty desperate.

    Van is a 55 plate. First problem is I don't have any DTCs to help here. Looking at the dash there doesn't seem to be an MIL light and I cannot find a diagnostic socket anywhere.

    Van seems to drive pretty good overall... But... If I rev high in say third, then lift of the throttle for 5 seconds (or if I've been engine braking downhill), so on the overrun, then I plant my foot to the floor I get absolutely no response. I ease off the throttle and I hear a kind of pop as pressure releases and I get an almighty cloud if blue smoke out the exhaust. Then I ease back on the throttle and all is fine.

    I suspected maybe the turbo vanes seized. Nope, I can move them by hand. Vacuum gauge between turbo and solenoid, good amount of boost in neutral when I kick the throttle. But it doesn't move the actuator. (I read online I should see this actuator move even if revving in idle, although this needs clarifying... I wouldn't have though I could over boost with no load). I beleive actuator is good, I blew hard down the line and could just feel it move slightly.

    So... I suspected N75 valve not sending pressure down to actuator. Replaced, still the same.

    Next, I know the map sensor and the n75 have a relationship. I was getting suspect results when metering the map, so I swapped that. Issue still persists.

    Something else I have noted... In neutral, rev the engine, when revs get back down to idle the engine shudders as if it'd about to stall and I get a puff of blue smoke that seems to come from the joint of the pipe connecting exhaust manifold to egr valve. The puff comes out if manifold end. The engine has stalled completely on a couple of occasions doing this, although seems to be a slight improvement since replacing the map.

    I really don't know where to go next with this. Should I be seeing that actuator move at idle? If so, although I can move the vanes by hand perhaps they are too tight for the actuator to move them? Or maybe I'm barking up the wrong tree entirely. But I have no idea what tree I should bark up next.

    Any help and advice much appreciated.

    Carl
     
    0 0 0
     

  2. Re: LT35 2.5TDi no power and blue smoke after overrun 
    #2
    Join Date
    Aug 2020
    Location
    HemelHempstead
    Posts
    1
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    Hi did you solve the problem? I have exactly the same problem with my LT35 ??
     
    0 0 0
     

  3. Re: LT35 2.5TDi no power and blue smoke after overrun 
    #3
    Join Date
    Mar 2017
    Location
    Cornwall
    Posts
    2
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)
    New valve stem seals
     
    0 0 0
     

Similar Threads

  1. Blue smoke + lack of power - help please
    By bag320 in forum 1.8T - Engine
    Replies: 7
    Last Post: 30-11-2010, 03:54 PM
  2. blue smoke on overrun
    By apache2020 in forum Audi A6 - C5 Forum - 1998 - 2004
    Replies: 6
    Last Post: 31-08-2010, 08:53 PM
  3. power loss and loads of blue smoke
    By tennentsfan in forum Alhambra
    Replies: 11
    Last Post: 03-10-2009, 05:31 PM
  4. Audi A6 2.5tdi Blue smoke.
    By richie3210 in forum A6 - S6 - RS6 - - Archive Topics
    Replies: 1
    Last Post: 16-03-2008, 08:15 PM
  5. Repeting blue smoke 2,5tdi afb
    By sofoiks in forum A6 - S6 - RS6 - - Archive Topics
    Replies: 0
    Last Post: 12-02-2008, 02:10 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 -