1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

2.0t fsi complete boost loss

Discussion in 'Audi S4/A4/A4 Cab (B7 Chassis)' started by Roadrunner146, Oct 28, 2013.

  1. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Hi fellas.
    Wondered if you can help me agin.
    Driving to work this morning in the torrential rain and I lost all boost pressure. Tried turning engine off and on again to reset, but nothing.
    Plugged in my phone to use the Torque app that i have, checked for faults , and nothing. Nothing on the dash either. Still the same on the homeward journey to.
    I do get a small pressure reading through the Torque app, buts its just the standard pre readings you get just before the turbo spools up.
    The DV has already been changed for the upgradded version, and I have tried the oil cap removal while engine running test, but no real issues there.
    Does anyone have any idea.
    Thanks

    Brad.
    #1
  2. bez101
    Offline

    bez101 Yorkshire & Humber Rep. Regional Rep

    Joined:
    Jul 8, 2008
    Messages:
    8,679
    Likes Received:
    20
    id check the Dv
    boost pipe
    ic pipes
    #2
  3. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    If the pipes or pipe have come loose, would I hear any hissing sounds.
    #3
  4. NHN
    Offline

    NHN Modmetractor Site Sponsor

    Joined:
    Jan 14, 2008
    Messages:
    27,217
    Likes Received:
    29
    As above, check IC/boost piping.
    #4
  5. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Trust it to happen when we have just changed the clocks.
    Thanks fellas, i will check them on friday afternoon.
    Brad.
    #5
  6. sewell10
    Offline

    sewell10 Member

    Joined:
    Dec 19, 2010
    Messages:
    225
    Likes Received:
    0
    Buy a boost gauge
    #6
  7. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Right, I have checked my pipes, and all seems ok. I even pulled the new DV out to check it over, but there's not a lot that can go wrong with them.

    What can I check for now. It's been a bit frustrating driving, knowing I have no power.


    On a separate matter. While I was under the car, I noticed red fluid under the passenger side engine mount. Does this mean it has failed, the car has been feeling a little rougher than usual lately.


    Thanks

    Brad.
    #7
  8. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    I have read that the PCV valve is a weak point, could this be the problem.
    #8
  9. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Can someone point me to the right place for the boost piping. I have checked the ic pipes under the engine. But I am not sure which pipes are the boost one's.
    #9
  10. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Right, quick update.
    I have had another look and I have noticed that the long rod coming out of the back of the pressure unit is not connected to anything. Is this normal, it seems strange to have that long rod their with a threaded end and it not be connected to anything.
    Also, I removed the lower passenger side IC pipe to check for small splits, and when I did so about 50 to 70ml of oil poured out on my driveway, again, is this normal.
    Sorry for all the questions, but I just want to make sure I have covered everything before I give in and take it to a garage.

    Brad.
    #10
  11. Broken Byzan
    Online

    Broken Byzan Photographic Moderator Staff Member Moderator

    Joined:
    Apr 26, 2004
    Messages:
    12,568
    Likes Received:
    9
    oil can be normal if never emptied, it settles at the lowest point.

    This rod, is it at the back of the turbo?
    #11
  12. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Yes. A pipe links the DV to the pressure unit.
    #12
  13. Broken Byzan
    Online

    Broken Byzan Photographic Moderator Staff Member Moderator

    Joined:
    Apr 26, 2004
    Messages:
    12,568
    Likes Received:
    9
    AHA, that'll be it. It's supposed to be connected via the nuts to the arm which activates the wastgate. Without it, boost is just vented away
    #13
  14. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Its going to be fun connecting that back up. I can just about see the waste gate on the back of the manifold. Looks like I will be getting some grazed knuckles tomorrow. Does anyone know what the connection at the waste gate end looks like. Brad.
    #14
  15. Big Al
    Offline

    Big Al A4 2.0T FSI Quattro

    Joined:
    May 23, 2011
    Messages:
    349
    Likes Received:
    1
    Does this picture help? The turbo bypass valve is removed in this shot. The wastegate vacuum unit is visible at the top with the actuator rod coming out of it going to the wastegate (bottom rhs) on the turbo.

    [​IMG]
    #15
  16. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    I can't quite make out the connection in that shot, but thanks Al.
    I have managed to find a linkage picture, but it's from a Golf, but it does give me an idea of what I'm looking for. HPIM1997wcomments.jpeg
    #16
  17. lynallbel
    Offline

    lynallbel Member

    Joined:
    Oct 9, 2013
    Messages:
    395
    Likes Received:
    0
    Dont turn the rod itself or you will tear the rubber inside the actuator.


    Lynall
    #17
  18. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Thanks for the advice.
    #18
  19. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Hi all.
    I've managed to sort the problem out, but it was a lot more evolving than I originally thought.
    The waste gate actuation rod had actually snapped. So a bit of head scratching, I came up with a plan to repair it.
    While removing the N75 valve, if that's what it's called, I managed to snap a small plastic pipe off a small switch located next to it.
    So two repairs to do.

    Been for a drive and I have my boost back, but not quite the same.
    Boost comes in, but higher up the rev range and not quite as strong.
    According to the boost gauge, I'm getting 4.8psi which is not full boost.
    Am I right in thinking that the actuation rod is adjustable, if so, which is the correct way to adjust it, either clockwise or anticlockwise.

    Here's some pictures of the repairs I did. The bolt used to fix the rod is a worktop connecting bolt. Worked a treat. And dont panic over the amount of glue used to fix the snapped pipe. It was super glued first, then epoxy resin spread around to give it some strength. 20131103_133952.jpg 20131103_152035.jpg
    #19
  20. pablo
    Offline

    pablo Member

    Joined:
    Aug 7, 2006
    Messages:
    801
    Likes Received:
    0
    the length is critical as youve found out you wont get full boost otherwise.

    what a mare :(
    #20
  21. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    What is the standard boost for a 2.0t fsi psi wise.
    I will need to know this before I alter the length of the bar. Don't want to over boost.
    #21
  22. Giosabcsl
    Offline

    Giosabcsl Member

    Joined:
    Mar 23, 2013
    Messages:
    423
    Likes Received:
    3
    12-13 psi, 2800 rpm is when you make peak boost or around there.
    #22
  23. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Thanks.
    #23
  24. Stringster
    Offline

    Stringster Missed gear

    Joined:
    Jan 16, 2006
    Messages:
    389
    Likes Received:
    0
    There is some information here that may help.

    Looks tricky to get the right adjustment / length. Good luck!
    #24
  25. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Thanks for that.
    I have read a few threads on the subject. But because of the unique way my actuation rod broke and how it's been repaired, it should be a simpler job.
    #25
  26. Roadrunner146
    Offline

    Roadrunner146 Member

    Joined:
    Apr 15, 2012
    Messages:
    55
    Likes Received:
    0
    Well I managed to get under the car this morning, and what a PITA. 2 and half hours it took me.
    When fitting the worktop bolt the first time, it must of wound in what was left of the actuation rod back into the adjuster, making the rod to short. I nearly lost the thread completely.
    The only way I could think of to stop the thread rotating was to file down another bolt to lock the thread to adjuster, and it worked a treat.
    While driving I am hitting peak boost at 14 psi, but normal acceleration, I am getting 7 to 9psi. I could tweak a bit further, but I am happy with what I have got. Not bad fix for £5 for bolt and super glue.

    Thanks for all your help and advice fellas.

    Brad. 20131108_125431.jpg Screenshot_2013-11-08-13-31-35.jpg
    #26

Share This Page