JMB RetrofitsChris Nott
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  1. #1
    speedicar225's Avatar
    Phlat6

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    2002 S3: Exhaust manifold replacement

    Hello,

    Just purchased this car knowing the exhaust manifold would need replacement.

    I am not particularly interested in increased performance and really want a "relatively" easy replacement for the existing rattler.

    Is there an aftermarket manifold, which will accept all of the standard equipment that can be recommended? Would a VAG replacement be a better proposition?

    A competent and reliable fitter would also be required. I am in South Wales, but quite happy to travel cupla 00 miles for the right service.

    Any help would be greatly appreciated.

    Thanks.

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  3. #2
    HTC
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    Rattling not blowng?

    Rattling would suggest the downpipe. A faulty manifold would "tick" like a tractor.

  4. #3
    speedicar225's Avatar
    Phlat6

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    Thanks for the help.

    That's thrown me a bit as I was quite sure the problem was the manifold!! Seemingly some form of inner skin or lining gets partially detached and vibrates/rattles at certain engine revs. If it is the downpipe, is this a fairly common problem, in your experience?

    Thanks.

  5. #4
    1st Gear

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    I have just put my manifold back on and its a cast iron jobbie, so I doubt anything is wrong with it. It is most likely one of you heat sheilds down the back of the engine bay hitting the downpipe, I say this as I had my downpipe off also and I can't see what could have gone wrong with yours.

  6. #5
    2nd Gear

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    standard mani on my a3 quattro, standard turbo. only ever had a revo trial. manis cracked big time! 3/4 cracks in it. 120k miles. cant wait to get my nice new one on!

  7. #6
    Prawn's Avatar
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    I was going to say, the manifold is just a big cast lump, theres really nothing in it that can rattle!

    it's possible that as the engine moves your downpipe is hitting the subframe and vibrating, but to be honest, it sounds to me most likely to be the cat head shields, which famously come off and rattle like hell!
    -------------------------------------------------------------------------------------------------

    Prawns TFSI Turbo'd 1.8T Track Car

    But I know nothing so ignore me.

  8. #7
    HTC
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    The B5 S4 has twin skin manifolds. This design is required to prevent heat transfer into the engine bay due to the very crowded location of the turbos. They break and rattle on pre 1999 engines.

    Audi didn't use this system on the A3/S3. The manifold is one peice, but the downpipe does have an outer skin of sorts.

    Here's a picture of the S3 manifold



    Here is the S3 engine bay with the head and manifolds removed. Notice the shield around the downpipe.



    It may be this or even something further down. Best to get the car on a ramp and have a listen.

  9. #8
    speedicar225's Avatar
    Phlat6

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    Thanks again.

    I will do just as you suggest and get the thing off its wheels, have a rummage and a listen.

    Again, many thanks.

  10. #9
    speedicar225's Avatar
    Phlat6

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    Hello again,

    This noise is still present. The following has been done in an attempt to trace it:

    1. VAG COM thing is all clear and no problems at all.
    2. Remove belt and isolate a/c compressor, alternator etc: run the engine and no difference.
    3. Thought unlikely that it is an internal engine problem.
    4 There do not appear to be any leaks in the inlet or exhaust systems.

    Noise is best described as a tft tft tft tft (tft). Prevalent when the engine is cold and usually under load, but not every time. Seems confined to 2k-2.5k revolutions. It is possible to drive "round" it be easier throttle use.

    Car goes very well, but am tempted to think that performance is off a bit when we are "fluttering".

    My current bet is wastegate "flutter". What to do? Firstly ask you whether you would agree or have any other obs to make.

    I do not wish to be a bore and a pain, but whilst this problem annoys my main concern is to ensure that no lasting damage is done.

    Thanks again.

  11. #10
    S3 Paul's Avatar
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    How do...
    Right, i will list what i checked AND what i found my rattle to be, Hope it helps somewhere along the line...

    I had a funny rattle , I checked ALL the heat shields on the car ( not a 10 min job) then... checked the manifold for cracks... they are normaly worse ones the car is hot... no crack found. then the turbo to manifold gasket. all fine there. then i checked the heat shields against the air con pipes... slight marks so moved out of the way... downpipe removed with cats also... checked, nothing loose.
    Lastly.... the EGT sensor in the back of the turbo. the little bugger was loose !

    Be sure it is not engine related though... cam belt tensioner can go and sound like a buggered exhaust.
    Unclip the timing belt cover and check the belt is still under the corect tension.
    Noggy Blue 2001 S3

    I ask questions because i change my mind so much. If i ask questions you have already covered... just leave it be?

  12. #11
    speedicar225's Avatar
    Phlat6

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    Thanks for the help.

    Problems resolved today with the replacement of the DV with a new standard part.

    One issue left to chase down.

    Thanks again.

 

 

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