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'Vacuum' type noise on start up.

Discussion in 'A3/S3 Forum (8L Chassis)' started by lloydsta101, Nov 3, 2009.

  1. lloydsta101

    lloydsta101 Member

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    Hi there,

    Over the last few weeks I've been getting what can only be described as a 'Vacuum' type noise when starting up. This only happens a couple of times a day, usually when the car has been left for 4-5 hours. The odd thing is that it doesn't always do it on a morning, but nearly always does when I drive home for lunch and then again after work.

    It's quite a loud noise... like someone is literally standing next to the car with a vacuum, lol. If I leave the car running on the spot once started, the noise will continue for about 2 minutes. Although, if I drive away and give it a few high revs then the noise goes after about 5-10 seconds.

    Does anybody know what this is, as it's starting to bug a bit now?:uhm:

    Cheers in advance guys! :)
     
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  3. Broken Byzan

    Broken Byzan Photographic Moderator
    Staff Member Moderator VCDS Map User Audi A4 quattro

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    Secondary air injection pump. used on cold starts to inject air into the system to aid warm up of the Cat.

    Its probably leaking as they are made with silly little rivets that split away
     
  4. lloydsta101

    lloydsta101 Member

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    Thanks for the quick reply!

    Is that a hard thing to fix/change? Could I do it myself, or is it a garage job?
     
  5. Sandip

    Sandip Well-Known Member

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    Mines been doing the same, where abouts is this secondary air injection?
     
  6. djb83

    djb83 redline responsibly

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    same problem i have priced a secondary air pump was about £400 and the combi valve for it is around £80 :banghead: so its costly to say the least prices were from verve in wishaw scotland
     
  7. Sandip

    Sandip Well-Known Member

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    :blink:bloody hell £400!! Is it possible to bypass this pump in anyway or repair it?
     
  8. djb83

    djb83 redline responsibly

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    i know still working out if it is the pump i think ill change the combi valve 1st to see if that cures it lol
     
  9. will.f_1.8t

    will.f_1.8t Member

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    Its the air pump to heat the cat, is a really easy repair! search it, there is a how to guide which i followed and its cured the problem. its the seal around the casing which needs bolting together.
     
  10. lloydsta101

    lloydsta101 Member

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    I've read somewhere that it's because the standard secondary air injection pump has rivets on it or something, so you need to possibly drill them out and replace them with nuts and bolts.

    Sounds easy enough, but would be much simpler if I knew what it actually is and where to find it. :)
     
  11. djb83

    djb83 redline responsibly

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  12. Sandip

    Sandip Well-Known Member

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    :iagree: location location:)
     
  13. Sandip

    Sandip Well-Known Member

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    thanks for that djb83! i'll be investigating that asap!
     
  14. lloydsta101

    lloydsta101 Member

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  15. rossbrownlee

    rossbrownlee Ross_S4

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    Check the hoses for the secondary air before stripping anything though, should be one from the filtered side of the airbox down to the pump then another back up to the combi valve.
    Thay are about an inch diameter and corrugated plastic.
    These just have a clip connector which {should} have an o-ring in it too.
     
  16. Haglos

    Haglos jabba mapped

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    i done this proces on mine last week and it still makes that irratating noise and i dont want to source a new one for that price as it useless and the facelift s3 dont have it
     
  17. The Doctor

    The Doctor Well-Known Member

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    Why don't facelift S3s have it then?
     
  18. Broken Byzan

    Broken Byzan Photographic Moderator
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    they do dont they? in front of the engine under the Inlet manifold

    Facelift TQS deffo does
     
  19. NHN

    NHN Retrofitter - Audi - VW - Skoda - Seat
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    Its definitely secondary air pump, could have got water in aswell which makes them bloody noisy, had 2 swapped on my s3.

    yeap facelifts as we confirmed before Mark have them, show in etka
     

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