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2000 Sport TDI - Limp Mode / Over Boost

Discussion in 'A3/S3 Forum (8L Chassis)' started by ruffrida, Feb 27, 2012.

  1. ruffrida
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    ruffrida Well-Known Member

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    [Feb 27, 2012]
    Hi Ya'll,

    Now ihave a new problem, but it is an over boost issue so not that much of an issue, MAf? Egr? or N75?

    Basically the car revs fine untilll you put it under extreme load, ie, high revs going up an hill, car backs off like it has lost boost or turbo, very random !!

    I have taken it for a good run today and i am convinced it also juddrs slightly when going up a gradual hill in limp mode.

    Happy to hear all sugestions, feel free,

    Thanks
    #1
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  3. BuckleyTDI
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    BuckleyTDI Member

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    [Feb 27, 2012]
    hey

    if it your usual high milage car then you it will 9 times out of ten be the varibale vanes sticking in the turbo. you could run a innotec turbo cleaner kit through it which is reasonably cheap round 70-100 quid job done. only prob is this doesnt always cure the probelm, so you could either replace the turbo unit or get the turbo reconditiond. if this is the problem then when sorted you will see a vast improvment in drivability of the car and no more lip home mode. usual fault codes thrown up will be "charge pressure control" negative deviaiton. get it on the vag com first tho before jumping to conclusion as this could prove very cost effective.

    james
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  4. ruffrida
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    ruffrida Well-Known Member

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    [Feb 28, 2012]
    Hey james,

    Never even thought of that, after reading all the faults on here for N75 failure i just presummed it was that or the Maf, i have ordered both anyway just in case.
    I will have a look for these turbo cleaners, its totalally new to me.

    Cheers for the advise, will keep you posted.
    #3
  5. ruffrida
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    ruffrida Well-Known Member

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    [Feb 28, 2012]
    #4
  6. 666markyboy
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    666markyboy Well-Known Member

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    [Feb 28, 2012]
    Or maybe you could try this http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html but note the post's made the guy called Turbo Unit ,,,, he might be right he might be not, i don't know .... i'm guessing he's in the trade of supplying replacement turbo's or refurbishing them so he might not want people to know about a quick and easy fix or he may indeed be telling the truth... read the thread and make your own mind up but it's seems to have worked for plenty of people
    #5
  7. ruffrida
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    ruffrida Well-Known Member

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    [Feb 28, 2012]
    That sounds like a plan, will be sending the misses out to get me some MR Muscle oven cleaner,

    Cheers Markyboy
    #6
  8. BuckleyTDI
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    BuckleyTDI Member

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    [Feb 28, 2012]
    yep thats the stuff but have also heard of the mr muscle being used before. i tried the innotec kit on my 130 TDI but it only made a slight difference and would still go into limp mode when under extreme loads. the turbo can be removed and stripped and cleaned which will work 100% but for the labour charge incurred then i decided to buy a new turbo for £562 genuine unit. this worked an absolute treat and is a different car now.

    james
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  9. ruffrida
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    ruffrida Well-Known Member

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    [Feb 29, 2012]
    Hi James,

    I think i wil lbe trying cleaning the turbo and replacing the maf & N75 before i go spending that kind of money, cheers fo rthe advice though.

    I have noticed this morning that it has now started to it at a lot lower revs, 5th gear about 2200revs it did it this morning.
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  10. BuckleyTDI
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    BuckleyTDI Member

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    [Feb 29, 2012]
    hey

    An easy way to check the vanes which if you have any form of mechanical knowledge is easy, would be to remove the actuator rod that connects the the vanes shaft. theres a little circlip on there they is easy to remove and remove the actuator arm from the vanes shaft. now try and move the vane shaft with you fingers, this should be easily done if it is hard to move and feels very stiff then this is defo the issue, as you should be able to flick it with you nail open, closed, open, closed, but if gunged up with soot then it will prevent it from moving easily hence casuing over boost and limp mode.

    james
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  11. ruffrida
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    ruffrida Well-Known Member

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    [Feb 29, 2012]
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  12. BuckleyTDI
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    BuckleyTDI Member

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    [Feb 29, 2012]
    yep thats exactly it but obviously there is alot involved and if this isnt the issue then it would be abit annoying to do all that to find it not that. so best thing to do would to try and move then before unbolting the turbo by removing the actuator rod.

    james
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  13. ruffrida
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    ruffrida Well-Known Member

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    [Mar 1, 2012]
    Yeh someone else said that last night, so i will be removing the actuator rod first then going from there, my new Maf has arrived today aswel just need to pick it up from post office,
    Cheers
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  14. ruffrida
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    ruffrida Well-Known Member

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    [Mar 2, 2012]
    Fitted the new Maf last night, great response when turbo kicks in round town, but as soon as you get in the high gears it goes into limp mode/ over boost again !
    Roll on saturday when i have the time to check the actuater, egr & turbo vaines
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  15. ruffrida
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    ruffrida Well-Known Member

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    [Mar 5, 2012]
    Recieved my new Maf, & N75 at the weekend !

    Tried both and it has made very little diffrence, whilst i had some time on me hands i also removed the throttle body which was full of s***e, cleaned it all back to shiney, but this has made no diffrence at all.

    My friend mensioned it could be the Actuator sticking, i have checked this but it only seems to move a very slight bit, and i mean not even a cm, is this right??
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  16. BuckleyTDI
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    BuckleyTDI Member

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    [Mar 5, 2012]
    could you move it easily, by easily i mean flick it from side to side or did u have to give it some effort? it should move really easily. mine was very notchy which i why i changed it and it done the trick. you could feel that it was all gunked up with soot.

    james
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  17. 666markyboy
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    666markyboy Well-Known Member

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    [Mar 5, 2012]
    i believe it's spose to move around 25 to 30 mm so it sounds like yours is all clogged up and the vanes need cleaning
    #16
  18. Cobra88
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    Cobra88 Active Member VCDS Map User

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    [Mar 5, 2012]
    Hi Guys

    I did the Mr Muscle clean and it worked a treat

    less than £3 and about 2 foot of screenwash tubing.
    different car ;)
    #17
  19. ruffrida
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    ruffrida Well-Known Member

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    [Mar 5, 2012]
    Hi James, no it would move a few mm, pushing down on the rod from above, it now aswel if you sit and rev it hard it makes a loud wastegate noise and cuts out compeltly
    #18
    SPORT BACK SI likes this.
  20. ruffrida
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    ruffrida Well-Known Member

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    [Mar 5, 2012]
    Defo not moving that far marky, i have only tried from above with the rod still connected as i could not remove it due to space and time, i have also been told, due to my engine been the AHF and not a PD it does not have a variable vain turbo, is this right??
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  21. BuckleyTDI
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    BuckleyTDI Member

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    [Mar 5, 2012]
    hello mate

    your engine does still run a VNT turbo the same as the PD,s, what you need to make sure is that you completely dissconnet the actuator arm from the vane shaft, and move it out the way just enough for you to be able to freely move the vane shaft backwards and forwards. it wont move with the actuator still attached. if you still have no movemen then, this will mean u vanes need a clean or new turbo time. where abouts are you as i dont mind having a look if your not to far?

    james

    james
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  22. ruffrida
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    ruffrida Well-Known Member

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    [Mar 5, 2012]
    Hi Bud,

    Im in wigan not sure where you are.

    Defo seems like i need to disconnect it and try it again
    #21
  23. BuckleyTDI
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    BuckleyTDI Member

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    [Mar 5, 2012]
    Oh that's bit of a trek, soz dude. Yer defo worth disconnecting if you have the time, it's the only way u can be sure it's that.
    Janes
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  24. ruffrida
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    ruffrida Well-Known Member

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    [Mar 6, 2012]
    Going to have a look at it again at the weekend as i come to work its dark, i go home its dark.

    I have noticed this morning that on start up in a morning it really struggles then once it starts its throwing loads of smoke out.
    #23
  25. Cobra88
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    Cobra88 Active Member VCDS Map User

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    [Mar 6, 2012]
    My VNT actuator moves about 10mm 1749V, VA, VB are all about 10mm (ie: not anywhere near 20-30mm) ;)
    #24
  26. 666markyboy
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    666markyboy Well-Known Member

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    [Mar 6, 2012]
    here ya go.... this shows how far it should move

    Last edited by a moderator: Aug 15, 2014
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  27. Cobra88
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    Cobra88 Active Member VCDS Map User

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    [Mar 6, 2012]
    Hi Marky

    when the VNT is actually assembled the rod moves approx 10-12 mm for a full sweep of the Vanes
    on all the GT1749V, VA & VB's i have here ;) (thats how far it moves here and the VB is brand new in Audi Wrapper (ie:not sooted up)
    that one has the ring & VNT removed so moves as far as the actuator will go.

    I only have these 3 to measure so other units may vary ;)
    #26
  28. 666markyboy
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    666markyboy Well-Known Member

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    [Mar 6, 2012]
    Ahh right .... good info then there Cobra cheers :thumbsup: .... that video is a little misleading then
    #27
  29. ruffrida
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    ruffrida Well-Known Member

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    [Mar 7, 2012]

    I was going to say good detailed video thanks, until i saw the quote below!!
    Last edited by a moderator: Aug 15, 2014
    #28
  30. ruffrida
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    ruffrida Well-Known Member

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    [Mar 7, 2012]
    Cheers Cobra,
    I have re checked it again and it moves about 5mm tops when conected.
    Thanks for the advise fella's only 2 more days till the weekend then can have another look, still got me can of mr muscle so hopefully ge ton that
    #29
  31. ruffrida
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    ruffrida Well-Known Member

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    [Mar 10, 2012]
    Hi,
    Welli have had the actuator off today and it moves fine !

    So onto the Vain clean, did as discribed, left for 2 hrs still no different.

    How far is the arm meant to move once the actuator is removed? As i did notice when i was re fitting the actuator the arm woruld only move a slight bit (couple of mm each way) and when i was trying to get the bolts back on i had to compress the actuator quite alot to get it tight, is this right?
    #30
  32. BuckleyTDI
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    BuckleyTDI Member

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    [Mar 10, 2012]
    do you mean the actuator moves fine, or the shaft it attaches to moves fine? the shaft it attachs to should move about 10mm from one side to the other with no resistence

    james
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  33. ruffrida
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    ruffrida Well-Known Member

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    [Mar 11, 2012]
    Yeh the actuator moves fine, but like i said on re fitting i have to compress the actuator quite alot to get the nuts back on, the arm only moves about 2mm either way
    #32
  34. BuckleyTDI
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    BuckleyTDI Member

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    [Mar 11, 2012]
    well that isnt how is should move defo around 10mm movement so if it not closing of enough you will go into overboost limpm mode

    james
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  35. ruffrida
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    ruffrida Well-Known Member

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    [Mar 12, 2012]
    Took it bit for the third time yesterday and the wastegate arm is sticking.

    Once the actuator is removed the arm is stuck in the down position and wont budge, until you prize it up with a screwdriver.
    When the arm is at the top thier is plenty of movement and you dont have to compress the actuator to re-fit. I sepent a good half hr just pusing it up and down trying to free it off as much as possible. It seems to be a lot freeier but still goes into limp mode.
    I have also done the mr muscle trick again which has seemed to make a diffrence as the limp mode does not kick in till their is a lot of strain / pressure.
    #34
  36. BuckleyTDI
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    BuckleyTDI Member

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    [Mar 12, 2012]
    thats the baby, i used the innotec kit which did make a difference, i seemed to go into limp alot later then before, but still did. only other choose it to take it of and strip it or new turbo time.

    james
    #35
  37. R-Tech-Nick
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  38. 666markyboy
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    666markyboy Well-Known Member

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    [Mar 12, 2012]
    Just for info,,, today i cleaned the inlet manifold out and also the EGR valve.... both of which were really full of crudd .... whilst i had it all apart i fitted a clean peice of silicone pipe to the actuator on the turbo to check the movement of the vanes and just by sucking on the pipe i was able to feel the actuator arm move a good 20mm ( no jokes about sucking please ) :) .... anyway my point is there's no need for a vac pump or anything to check it's all free ... my car was fine before the clean of the EGR so i'm guessing if you can't make the actuator move it's full movement by sucking on it yourself then there is a problem .... also RE: the EGR rather than block it off all i've done is remove the VAC hose that operates it and blanked it off with an old bolt or as some have mentioned a golf tee... so far no engine lights and the valve no longer opperates as it's in a closed state normally....... tickover on the car is a little smoother after cleaning everything but driving it just seems the same ... MPG may improve, i've got to do a few work runs before i'll know that but i'm glad it's no longer chucking all that **** in the inlet after what i cleaned out today
    #37
  39. 666markyboy
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    666markyboy Well-Known Member

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    [Mar 12, 2012]
    Thanks for the link to the Videos Nick i hadn't seen those before.... would you recommend a strip down and clean on a car with 130,000 even though it wasn't showing any problems ??? i prefer prevention rather than cure :) also Top work on Prawns car i've been following his thread very closely from the start as i own a 1.8t A3 also ..... well the wife does... even if it was mine :)
    #38
  40. ruffrida
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    ruffrida Well-Known Member

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    [Mar 13, 2012]
    #39
  41. ruffrida
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    ruffrida Well-Known Member

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    [Mar 13, 2012]
    I fitted a new vacum pipe to the actuator at the weekend as mine was that perished if you sucked onit (alot of sucking going on ere, lol) the pipe would close as it was that soft.
    back ion the day i had a Mg zs tdi, on which i blanked off the Egr which made quite alot of diffrence to its top end power, how much diffreence does it make with the Audi Tdi's??
    #40

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