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Diverter valve

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by Alan H, Mar 2, 2011.

  1. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    Hi all,

    Can a dodgy dv cause a drop in power?

    I have the 1.8T 163..

    The reason I ask is when I'm on about quarter throttle the car seems to really pull wel, but when I put my foot hard down the car seems to run more like a normally aspirated car rather than a turbo...

    I hope you guys get what I mean.

    TIA,

    Alan
     
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  3. docurley

    docurley Moderator
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    If you have a faulty DV it will effect the power for sure.
     
  4. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    In the way I've described?

    I know it's not the MAF sensor because I changed that some months ago (genuine BOSCH)

    Sometimes the car feels like a bloody flying machine, but then sometimes it feels lethargic....

    It's hard to explain.

    Plus it's not flagging any faults....

    Alan
     
  5. docurley

    docurley Moderator
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    Could be a faulty N75 or a loose/break wire to the N75
     
  6. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    N75?

    What's that?
     
  7. docurley

    docurley Moderator
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    Controls the boost.
     
  8. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    Thanks very much....

    Are they pricey to replace?

    Where are they situated?

    Thanks,

    Alan
     
  9. docurley

    docurley Moderator
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    There quite cheap and they are located depending on what 1.8T next to the DV which mounted on the turbo intake pipe if a 190bhp then the DV is mounted under the car by the drivers fog light.
     
  10. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    It's a 163bhp....
     
  11. docurley

    docurley Moderator
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    Then the DV will be mounted next to the N75 which will have a plug connected to it and two small pipes feedingoff it while mounted in to the intake pipe.
     
  12. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    Thanks for all the replies docurley.

    Looks like a job for the weekend....

    I will disconnect it and see what happens....
     
  13. docurley

    docurley Moderator
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    Also check all the vac line just in case.
     
  14. Q4

    Q4 Member

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    Good luck in finding the cause, when you do find it please let me know what it was as I have had this problem for a while and after much money spent with diagnosis and component replacement I have not yet got to the bottom of it!

    For info the car shows no engine error codes what so ever. Go figure !

    So far I have replaced DV, MAFF (twice), N75, coil packs, spark plugs, vac pipes, secondary air valve, both vac solenoids, fuel pump, fuel filter and intake temp sensor.

    My hesitation/flatness comes in around peak boost 3100rpm ish and goes at around 4k rpm. So far its been tracked down to the engine detecting pinking/Knock and then retarding the ignition timing hence the feeling of the car going flat.

    What has not been deteremined is the cause of the knock in the first place. Some theories are blocked intercooler causing high intake temp or intake pipe collapse or possibly dual mass flywheel breaking up causing vibration down the crank that is picked up by the knock sensors. No one has been able to say for sure the cause of the problem and the next "try it" options are starting to get expensive.

    Well good luck in finding the problem if you do find a cause then I would appreciate knowing what the problem was for you.

    If you need anymore info on my experiance just drop me a pm.

    Regards.
     
  15. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    That is not good...... :-(

    I'm going to try the N75 valve first.

    Do GSF or ECP do these or is it a dealer only part?

    TIA,

    Alan
     
  16. Tooks

    Tooks Active Member

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    Alan,

    I have a similar issue on mine, though only since remapping. It pulls really strongly on part throttle, but full throttle and it hesitates a little around 3 to 4k.

    I changed the DV, and no difference, though my old one was tired anyway. Next I tried a new N75 valve and chose the J version that is much talked about on here. It was a dramatic difference, the car felt so lively and pulled hard with no flat spot. I was very pleased!

    Alas, the full throttle hesitation returned a couple of days later, and also the car seemed to almost have a bad misfire even on part throttle. I put the old N75 back on, and normal service was resumed.

    So, I ordered a standard N75 from the dealer which has been upgraded over the years, and the hesitation was much improved.

    I've recently changed from Esso fuel to either Shell or BP, and the hesitation is now gone. I had to refill with Esso just last week, and my hesitation is back! Might be of help to you, might not!

    I changed all the coil packs, spark plugs and renewed all of the vacuum lines, two of which were split, before I started looking at the valves and I'm sure all that helped too.

    I think the N75 is a dealer order only, there are so many variations on it, your reg is the safest bet for getting the right one.

    Happy to lend you my 'J' valve for elimination purposes if it will help, but my engine didn't like it at all!
     
  17. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    Thanks Tooks....

    Does anyone have any part numbers at all? GSF have 2 options, would it matter which one I put on?
     
  18. Tooks

    Tooks Active Member

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    N75 'J' - A034 906 283 J - £51.40 + VAT
    N75 'E' - 06A 906 283 E - £36.70 + VAT

    My car is a 2002 model year 1.8t Sport quattro, part numbers are from invoices from two Audi dealers earlier this year, so should be current.

    The J valve is meant for an Audi S2, so the t piece pipes are the wrong way round for your car, so you need to turn it upside down. It sounds more difficult than it is, whichever one you buy just make sure the longest t piece goes into the same pipework as the valve you remove and you'll be good.

    Fingers crossed for you!
     
    #17 Tooks, Mar 5, 2011
    Last edited: Mar 5, 2011
  19. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    the part number on mine is 058906283 then a "c" stamped into the metal.

    does that make sense?

    I just phoned GSF and they didn't recognise the part number.
     
  20. Tooks

    Tooks Active Member

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    That's the same part number as my old one, it has been superseded by the E valve detailed in my post above.
     
  21. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    gsf didn't recognise that either.... :-(
     
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  23. Tooks

    Tooks Active Member

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    Yeah, they don't seem to be very good with some of these parts, which is why I ended up going to Audi for one.

    For the sake of a tenner or so, I thought it worth it.
     
  24. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    That's exactly what I've just done. £44 including the VAT and 10 minutes for me to fit it.

    Going out in a while so I'll see if there's any difference.
     
  25. Tooks

    Tooks Active Member

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    Excellent! :icon_thumright:

    Look forward to the report back!
     
  26. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    Plus the breather filter thing that sits above the n75 had a bit of gunge in it so I cleaned that out too...... it all helps.

    The trouble is I've got nothing to compare the car to, so I never know if it's performing properly :-(

    Wiil report back later on today......
     
  27. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    OK, just got back from doing a bit of running around and changing the N75 valve seems to have done it....

    It's not placebo effect either I've been very subjective with it and I can actually feel it trying to pull when my foot is hard down, whereas before I changed it the car just felt like an NA car.

    I'm not getting the slight surges (at very low throttle) either now that I was getting before.

    So hopefully this has sorted the issue out, but I will monitor it for a week or two first before giving it the full thumbs up.....

    Hope this thread is of some use to others
     
  28. Tooks

    Tooks Active Member

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    Good news! :)

    Fingers crossed it stays sorted.
     
  29. docurley

    docurley Moderator
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    Nice to here your sorted.
     
  30. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    I couldn't really tell earlier on because I was 5 up with the shopping.

    Just popped out with just the Mrs and I think I can say it's well and truly sorted. It's like a completely different car. I had to back off a bit, because I was still driving it like I was before and there was no need to......

    Next stop ....... re-map....
     
  31. Q4

    Q4 Member

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    Thats good news Alan, best I try another N75 then.

    Please lt me know in a week or two if it's still sorted the problem.

    Cheers
     
  32. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    I will report back. It has made such a difference to my car. When I got the car I was a little disappointed to say the least, but I got used to the low performance of the car and thought, well, I'll know not to go for another car like this.

    Having changed the MAF and now the N75 I have a renewed interest in it. But I want a re-map on it now, I want that extra bit of ooomph........

    :rockwoot::rockwoot:
     
  33. CMD

    CMD Pointing Forward's!!!!!!!!!

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    In short Badger5 is your man, pm the guy for your remap.
     
  34. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    Thanks CMD, has he got a website or anything?

    found it......
     
    #32 Alan H, Mar 6, 2011
    Last edited: Mar 6, 2011
  35. Tooks

    Tooks Active Member

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    I must admit, since I had mine remapped, I've fallen in love with the thing!

    I can toddle around town in it, waft along country roads, but when the mood takes or I need to overtake, it's a bit of a beast!

    Yes, I'm always tempted by the prospect of owning something much faster like an S4/RS4, but back in the real world I'm a happy chap.

    Two other things that I've noticed since the remap is the sound of the turbo working, and I get a couple of extra miles per gallon. :)
     
  36. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    I can imagine with around 200 bhp mine would be quite exciting too.......

    Might be a couple of months before I get it done though, winter has taken it's toll on the house and garden..... :-(
     
  37. CMD

    CMD Pointing Forward's!!!!!!!!!

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    His website is sooooo old but belive me when i say this guy knows is coconuts.. 1.8T are is specialty.
     
  38. saxonblue

    saxonblue Member

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    now this has got me thinking??
    i have just got a 1.8t cab, i love the thing , but i wouldnt mind a little more omphhhhh!
    yeah its fast inough, compaired to the 2.0i (130 bhp) i had prior to it its a hole new ball game
    woudl sticking a new n75 on it make a big improvement?
    ohh, the other thing is,,, i know this sounds silly but, what duz everyone else's turbo sound like, mine duznt have a wistle sort of noise( like on my old supra) insted it more like a raped fire pee shootre sound, lol i know its sounds like a dafe example!! but its like a tih tih tih tih tih noise,( **** at sound fx)
    is this normal
    seems to work fine???
     
  39. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    First thing to check is the MAF sensor. Disconnect it, then drive the car....you'll get the ESP light come on, but if it's the MAF you'll tell because the car will feel and pull loads better. Once you re-connect the MAF after a short while the ESP light will go off. (you will have a stored error code though, so you may want to get it cleared)

    A new MAF from GSF is about £60, but it's an exchange unit so you have to pay a £30 surcharge which get's refunded when you take the old MAF sensor back.

    This is an easy fix and takes about 20 minutes.

    I hear my turbo spooling up from about 2000 rpm

    Changing the N75 valve does make a difference if it's that that's broken....but my suggestion would be to get it on VAGcom to see if there are any other faults before parting with £45 for the N75 valve.
     
  40. saxonblue

    saxonblue Member

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    I think everything is working fine, i had the maf go on a b5 a4 a long time ago, n yeah, it duz make the car run like a old dog when they go, but mines ok,
    just whanted to know if the n75 would make the car more poke-ie, & how everybodys turbo sounded,
    mine kicks in at about 1800-2000 rpm, then the car realy wakes up, but i havent come across one making a sound like mine is , altho this is the first audi turbo i have owned,
    think everything is working fine, nothing opos up on my coad reader and the cars running fine
     
  41. Alan H

    Alan H Need a V8 or Bi-Turbo.......

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    If the N75 valve is dodgy, then it WILL have a detrimental effect on the cars performance, it will make the car lose boost. Mine was fine at part throttle, but put if I put my foot hard down there was nothing. It was like driving an NA car, no boost at all. The solenoid gets tired. It might be worth a punt just changing it anyway for the sake of £45
     
  42. saxonblue

    saxonblue Member

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    thanks, i may give it a go,
    still loving the car too much yet to get started with the plans i MAY have for it??? watch this space tho lol
     

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