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No Power. AFN TDI

Discussion in 'A4/S4 forum(B5 Chassis)' started by ScottD3, Jul 11, 2012.

  1. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 11, 2012]
    Morning all,

    On my way to Le Mans last week the car lost power going up a hill, it did the same when trying to over take someone.

    Foot down and no power.
    Limped it to the camp site and took a look at the engine.

    Unable to see any split pipes, any thing broken or hanging off.
    3 days later I limped it back to the UK.

    Its now at the garage getting some other things fixed before the turbo is looked.

    Things I've checked.
    Cables, pipes and plugs. All ok.
    Tested with out MAF, N75 and no change.
    Removed cold feed pipe to turbo and had a wiggle of the turbo, no movement up/down or left/right.
    No smoke or noise from the trubo, I normally get a slight whistle (no idea what that means).

    Tried moving the actuator arm but it never moved.
    Is it meant to move up/down freely or be hard to move?

    Checked the error logs and there was something about the manifold pressure but it never came back after I cleared the faults (I left the code at home).

    If any one has any ideas or thoughts please share.

    When the belts and pullies have been sorted out I will look at the trubo a bit more.
    I'm siding with stuck VNT vains the moment.
    #1
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  3. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 11, 2012]
    Also.
    Does any one know if the EGR solinoid is good replacement for the N75?

    I don't have a EGR, so that solinoid is not needed.
    #2
  4. AR-rkon
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    AR-rkon BZZZZ.... caffeine fueled electrical engineer Regional Rep

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    [Jul 11, 2012]
    It does look like the VNT, there is a cheap "mr muscle" fix on here somewhere, gotta be worth a fiver or so to try. failing that, i just took mine off, stripped the housings of each side of the CHRA and got myself covered in soot. but never had any more problems.

    As for the EGR actuator, it may work, but think it interprets the duty cycle signal differently to the N75...
    #3
  5. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 11, 2012]
    Thanks mate.

    I wont be swapping them over then.

    CHRA?

    I'm tempted to get the garage to take it off and me to strip it one evening.

    I read on another forum that someone uses N75e over a N75 and it was better.
    thought there was only one.
    Any one knows any thing about different types of N75s?

    Also, Does the TDI use the same N75 at you 1.8T guys?
    #4
  6. Reesy
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    Reesy Well-Known Member VCDS Map User

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    [Jul 11, 2012]
    Perhaps the car is the same, and you just woke up and actually realised your car is super slow.
    #5
  7. AR-rkon
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    AR-rkon BZZZZ.... caffeine fueled electrical engineer Regional Rep

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    [Jul 11, 2012]
    CHRA = centre housing rotating assembly... basically the middle (expensive) bit of the turbo....
    #6
  8. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jul 11, 2012]
    Just get it gunked full of mr muscle!

    TDI N75 is totally different to the 1.8T item.
    #7
  9. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 11, 2012]

    Wont be doing that then. lol
    #8
  10. PAULF
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    PAULF Active Member

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    [Jul 11, 2012]
    Scott,

    If you hook up VCDS, got to basic settings group 11, the N75 will operate every 10 seconds. Go and watch the actuator, and it should move up and down. If it doesn't, it could be either the N75 or the vanes. If you can't move the actuator by hand, it is most likely the vanes.

    I have carried out the Evilscotsmans Mr Muscle fix (Un-Sticking Your TDi VNT Turbo Vanes..... ) and found it worked great.

    I did give my actuator a lever up a couple of times during the wait, and could feel the carbon let go.

    Don't get hung up on the stuff leaking where it shouldn't, or eating away your ally housings/turbine blades/children or any of the other scary guff that has been spoken of by some folk (just use a bit of common sense - such as don't leave it sitting in there a few months before running the car or wash it off if it gets spilled!)
    #9
  11. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 12, 2012]
    I got a phone call from the garage this morning.
    They fitted a new belt and tensioner, took the car out for a test drive and agreed about the turbo.

    Had another phone call about 3 hours later saying the turbo is off and ready for collection.
    I was a little bit shocked cause I mentioned to them about the sticking vanes and stripping the trubo down to clean them.
    It would appear they agreed with me bout the vains and found them sticking, removed the turbo for me to strip.

    I'll pick it up tomorrow to try and strip it down this weekend to give it back to them on monday.

    Any one got any advice for stripping a turbo down?
    #10
  12. PAULF
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    PAULF Active Member

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    [Jul 12, 2012]
    #11
  13. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 12, 2012]
    #12
  14. PAULF
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    PAULF Active Member

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    [Jul 12, 2012]
    I mean when it's in bits!

    Carbon can be a right bugger to remove handrualically
    #13
  15. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 12, 2012]
    Belt sander and some 40 grit?
    #14
  16. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 16, 2012]
    Phone call from the garage.

    Car is now working.
    Replaced a couple of hoses and fitted my old turbo that I cleaned.
    All up and running better and quicker than before.

    Happy days :thumbsup:
    #15
  17. Foxmeister
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    Foxmeister Fired Up!

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    [Jul 16, 2012]
    Good news, hopefully wasnt too costly?
    #16
  18. ScottD3
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    ScottD3 I want your faulty electronics

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    [Jul 16, 2012]
    Bout what I thought it would be with a tidy little discount on top. :)

    I'm happy with it.

    I'll pick it up soon and see if its improved like they said.
    #17

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