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UrS4 auto rough running

quattrokid Jul 24, 2012

  1. quattrokid

    quattrokid Active Member

    "Suzi" ( NAME OF THE CAR) :) has this optional extra

    normal service is fine, niiiice smoooooth ride.... THEN it feels like a switch is made in the engineroom dept, then it feels lumpy as your grany's custard

    feels like I lose a cylinder but when i give it a light dabble on the go faster pedal, it smooths itself out again

    Grizz mentioned the harmonic damper is tired so have a good replacement lined up being fitted in Sept along with the gearbox change.( 236000 miles on this one aint bad) ( multi function switch is playing up)....anyway....

    The other day sat at the lights I put the car into Neutral and the engine was rocking!! circa 800rpm definately felt like it wasnt firing on all 5 pots or maybe it was but missfiring badly.

    I had the idle position sensor changed recently because the 1 already there had a few codes on vagcom pointing to it ( still got the old one)

    my vagcom doesnt like Suzi so wont work because its not a few hundred quid genuine lead

    any suggestions what else it could be please?

    what would the symptoms be on a dying coil pack ? ( I have had changed 1 or 2 the previous times I have owned the car)
    would the harmonic damper feel like its lost a cylinder when its worn out?

    could it be the MAF?
    normally Suzi is quiet quick for an ole girl but when this sensor/ switch thing does its thing, She is slow to pick up, feels lumpy and cant be ***** or is that me ? lol
    in fact the sensation is like driving a manual car too slow for the gear your in, jerky progress but when i give it more revs its smooths itself out but acceleration isnt as hard as it should be regardless of speed.Even at motorway speeds all will be well then suddenly this shuddering sensation kicks in and its down on power as well, stamp on the throttle and it will smooth itself out again!
    99% of the time the car is as it should be and pulls really well, other times when She's rockin' acceleration is lethargic to say the least..

    any suggestions please? i dont think its mechanically sourced otherwise it would be doing this all the time :(
  2. gen.heinz guderian

    gen.heinz guderian Well-Known Member

    which Audi is it? Have the injectors been cleaned?

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