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strange noise on start up & turning off

Discussion in 'A3/S3 Forum (8L Chassis)' started by jonS3, Oct 16, 2006.

  1. jonS3
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    jonS3 Member

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    noticed this the other day, it doesnt do it every time, but usually when cold

    once the engine is started up, a high pitched whine occurs. If the engine is turned off soon after the noise winds down. it sounds like when you switch off a high powered hoover.

    anyone got any ideas? :rolleyes:
    #1
  2. turbodan
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    turbodan Member

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    My MR2 Turbo made these noises once, i think it was something to do with coolant? there was a smell of burning rubber after a while and chen i checked the coolant i discovered that there wasnt any! and the top of the rubber hose was burning! im probably wrong but worth checking the levels out & see if you have a leak.

    Think i may have heard a similar sound when i owned a 306 but was something to do with the steering?
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  3. Lovegroover
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    Lovegroover Member

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    I'm sure i read somewhere before about a fan or blower unit attached to the exhaust to stop stalling on start-up.
    Basically it runs on initial start-up for a few minutes to make sure exhaust gases don't back up in the system i think?? :sos:
    Anybody shed more light on it.....
    #3
  4. pablo
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    pablo Member

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    i think its for emissions but it sounds like a harsh sucking noise it isnt high pitched.
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  5. Adams3
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    Adams3 Member

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    The classic jet engine noise!! lol

    Its your secondary air pump, very common fault.
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  6. jonS3
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    jonS3 Member

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    ive checked all levels and they're fine

    how hard/expensive is that to fix? :unsure:

    cheers

    Jon
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  7. Adams3
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    Adams3 Member

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    Its about 85-90 quid for the part from the stealers, not sure about fitting though.

    Im just leaving mine how it is!! i like the noise lol
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  8. mad max
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    mad max sixth gear

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    if your car is pre-facelift it will be secondary airpump,sounds like an old hoover but only comes on when the car is cold think you can have it disconnected
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  9. LaSarthe&Back
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    LaSarthe&Back Member

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    PMSL
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  10. jonS3
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    jonS3 Member

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    yeh mine is pre-face lift.

    what does it actually do? I'm guessing it does no harm then, but i'd like to get i fixed, is it easy to do?

    cheers
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  11. jonS3
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    jonS3 Member

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    does anyone know if this is going to cause me a problem? I'd obviosuly like to fix it, but not sure how hard the part is to change?

    any ideas?
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  12. HTC
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    HTC Active Member

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    Pumps air into exaust system during warmup to heat the cats up quicker. Emmisions device to lower pollution etc.
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  13. Adams3
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    Adams3 Member

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    I was told it was to prevent the cats getting covered in unburnt fuel, not sure now!!

    Its still working when its like that but obviously not to its full potential, not really doing any harm!!
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  14. benk
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    benk Member

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    The secondary airpump is used to get the CAT up to temp on a cold start. On my Skoda it goes for almost exactly one minute, with revs at 1200, then drops to 1000 and the pump goes off, and engine sounds a lot happier and quieter.
    I had mine checked by the dealer and they said it did seem a little noisy; they cleaned the throttle body and airpump and it has helped a bit. It still does it, but nothing like as noisily. They actually said they found an error code from the throttle body and that if it does it again then they would replace the throttle body. I think I will arrange to drop in and let them check it again before my warranty runs out... a new throttle bosy costs something like 400 quid I think.
    #14
  15. jonS3
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    jonS3 Member

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    thanks for the info benk, does anyone know where its fitted exactly?
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  16. sjokolademelka
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    sjokolademelka Member

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    Hangin onto this one too.. I have post-facelift, but also the squeal upon startup.. at first you could think an old car with a screaming auxillery belt, but..

    Did you have yours fixed Jon?
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  17. jonS3
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    jonS3 Member

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    just bringing this thread back up again, has anyone ever had there's replaced?
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