Adjusting Actuator & N75 Valve & AUM/AUQ Sort your boost leak issues thread...

Discussion in '1.8 & 1.8T' started by Richard Mk2, Jul 3, 2010.

  1. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    I recently had my Mk4 Golf AUM re-mapped by Custom-Code.

    Been reading various threads and info on the net, and apparantly the factory Actuator is adjusted to match the standard boost.

    Now that its running over 200, to get the car to boost at increased PSI, would require the Actuator to be slightly adjusted.

    How would i go about adjusting the Actuator. I heard you only need to turn a couple of threads at a time (on the wastegate settings/locknuts) max and mark the original position, too much and it could blow the turbo!!

    Any more info on this?

    Also, has anyone adjusted theirs and noticed an increase in boost. Mine seems to feel underpowered the last few days.

    Could be due to a faulty N75 valve perhaps.?

    Ive heard that you can adjust the amount of air which should leave the N75.

    Is this also true?
     
    Last edited: Jul 3, 2010
  2. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    bump.....
     
  3. badger5

    badger5 Club GTI Sponsor and Supporter Trader

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    dont adjust the actuator.
    the ecu has request boost which is measures via map sensor and n75 valve regulates boost to the actuator. if you adjust wrong way and cause a deviation over 250mb it will drop into limp mode.

    if its running fine, no benefit or reason to adjust this
     
  4. MUSHY 16V

    MUSHY 16V Moderator Staff Member Moderator

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    don't know bud i only have a tdi but if it over or under bosts it go's in to limp mode = no power
    vac leak or MFA would be my guess to the loss of power
    number 1 vac leak
     
    Last edited: Jul 3, 2010
  5. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    Thanks for the reply. Will not adjust the actuator then.
    Dont want to cause myself more problems. :thumbup:

    Dont get me wrong, the car does feel quick, but seems to loose steam up the rev range.
    Also when at the lights after driving, it doesn't seem to pull off as quickly. But if i turn the ignition off, then on again, it has more boost and feels quicker? [:s]

    Could the N75 be faulty? Or maybe a boost leak somewhere.
     
  6. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    :thumbup:

    Im thinking there maybe a boost leak somewhere.

    Are there any common places to check?
     
  7. turbotommy Forum Member

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    Vac or boost leak is top of the list!
    the pipes by the dipstick are prone to splitting,also the PCV and breather that comes from the rocker.
    Get the magnif/glass out mind as they are hard to spot.
     
  8. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    Going to give it a good going over tomorrow.

    I recently replaced the y shape breather pipe on the right side of the head, as this was split before. Wish i had replaced ir with a silicone one now though.
     
  9. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    Also, would a boost leak suggest why it runs better when turned off and on again?
     
  10. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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  11. Matt82

    Matt82 Forum Addict

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    dont touch the actuator

    for boost leaks look under the unlet manifold where it goes to the breather system

    i fixed two today, its that common, and then one had a dead one way valve too.

    tested for boost leaks and only found them around the dv connections

    also, if your dip stick tube is broken then it will be dragging in unmetered air
     
  12. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    I did recently replace the y shaped breather hose, and also noticed that the pipe beneath the inlet manifold had a little split. I basically wrapped a rubber hose around it, and jubilee clipped it tight.

    But going back to the Vortex link above ^^^ the guy has completely removed all the pvc system, plus others.

    Would it not cause any problems?
     
  13. Matt82

    Matt82 Forum Addict

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    yeah, it needs a pcv system just like any engine

    the one under tha manfold that goes to the one way valve and pcv, if its split, you can split it and bung it with a bolt etc. thats a good temporary measure
     
  14. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    I suppose its worth replacing then :thumbup:

    I guess it would be a good idea to replace the vac hoses with silicone replacements, to prevent any leaks in the future.

    Its just so hard to get to the ones under the manifold. Even before when i temporally fixed the broken one, even with the metal plate out of the way it was awkward!!

    Also dipstick tube is ok as i checked this for the common splits :thumbup:
     
  15. Matt82

    Matt82 Forum Addict

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    there are two 5mm allen bolts to remove the tray. three 10mm bolts to detatch the sai hoses and then the n249 can be swung out the way... then youve got access to your breather hoses
     
  16. turbotommy Forum Member

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    I run an AUQ daily driver which is the same an an AUM,i also have the same sort of vac/boost leak problems,my "Y" pipe is split amongst others and i must sort it all out.
    One of the problems is the N249 pipes are a maze and not easy to get to without snapping your dipstick etc...
    What we need is a good AUM/AUQ sort your issues thread ;) :thumbup:
    I put this highest in the list before engine tuning as you'll never get it right before sorting these issues.
    No point turning up the boost for it to leak more [:s]
    Interestingly other engine codes of simlar age use hard pipes and different config's for the breathers and i think a catch tank is the way forward with the "Y" pipe,its just a matter of going through the whole system bit by bit eliminating leaks or problems but a step by step guide is what people need (IMHO)
     
  17. Richard Mk2

    Richard Mk2 Paid Member Paid Member

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    Great idea Turbotommy!!! :thumbup:

    This diagram may help -

    [​IMG]
    [​IMG]

    This guy has completely replaced everything with silicone hoses!!

    Thats what im aiming for tbh, but will all be in black ;)
     
    Last edited: Jul 3, 2010

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