No boost dilemma on 2.0 CBBB...

Discussion in 'Audi TDI forums' started by stephngaz, Jan 12, 2017.

  1. stephngaz

    stephngaz New Member

    Joined:
    Jan 11, 2017
    Messages:
    2
    Car:
    2010 Audi TT tdi S-Line, 2007 A4 2.0 tdi
    Location:
    Nigg, Ross-shire
    Hi folks,

    My wife's 2010 TT tdi has been suffering the dreaded P0299, limp mode fault but all efforts are coming to no avail.
    After having the turbo off and cleaned (nightmare!!!) found the vnt actuator to near dead so was replaced with new Audi spare which I set up using vcds and mityvac.
    I also checked the n75 solenoid using "Basic Settings" test and it moves freely with 0-20" vac when cycling on/off. Plus the exhaust changes hopefully confining the vanes are actually moving.
    Problem is i have near zero boost and limp mode cuts in after 200 yards.
    The "turbo" graph looks like this:
    [​IMG]

    I'm just hoping there's someone out there interpret the graph for me. Looks like no boost from turbo or no reading.
    I'm fairly confident on all motor issues but this one is killing me and I'm sure I missing the obvious...
    It's a 2.0 CBBB engine with 72k miles.
    Just donning the coveralls to go back under again!!!

    Anybody help??
    [​IMG] Attached Thumbnails
     
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  2. Erich

    Erich New Member

    Joined:
    Jun 28, 2015
    Messages:
    18
    Car:
    Vw Jetta tdi 2000
    Location:
    burlington
    Can you fully move the vnt actuator arm easily manually with your fingers without it binding up on something?


    Sent from my iPhone using Tapatalk
     
  3. stephngaz

    stephngaz New Member

    Joined:
    Jan 11, 2017
    Messages:
    2
    Car:
    2010 Audi TT tdi S-Line, 2007 A4 2.0 tdi
    Location:
    Nigg, Ross-shire
    Yeah, the actuator lever moves very freely, maybe a little too easy...
    I'm seriously close to removing the turbo again to check the vanes as I can't see any boost but strangely can hear the exhaust note change during testing of solenoid n75.
    It looks like the vanes aren't moving.
    I'm stumped......
     

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