When switching off engine and taking key out, there follows a knocking sound lasts about 8 seconds then stops. Only happens after car has been for run, will not happen when just turning engine on then off.

9 Answers

  • 1 decade ago
    Best Answer

    this sound only happen when you turn off your car after it has been running for sometime only, right?

    i guess this sound is the cooling fan (radiator fan) because after turning off the engine it takes few seconds for it to come to a rest and stop moving coz of it interia, so i think the sound you hear comes from there!

  • 1 decade ago

    You mean it sounds like the engine is shuddering and trying to keep running? That is "running on", it's because something in the cylinders is too hot and still igniting fuel after the ignition is turned off. Basically it's trying to be a diesel. Could be plugs, could be a weak mixture, could be an induction air leak, could be a build-up of carbon.

  • 1 decade ago

    Your local Audi dealership has the updated scan tools to "plug in" as a previous user informed you. From that plug in they can determine if you need any updates, if there are technical bulletins, or if there is a serious engine issue. It is best to go to your certified local Audi dealership because not all service shops are equipped with the proper scan tools made especially for your Audi.

    Source(s): Audi of America Employee Altamonte Springs, FL
  • L G
    Lv 6
    1 decade ago

    The car is running on, a sensor is faulty you need to take it to the dealer and have it "Plugged in" this will show up what the problem is.

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  • Anonymous
    1 decade ago

    Timing fault causing 'running on'. Best to have the ECU checked out as damage will occur. Burnt valves or even a holed piston. Trust me.

  • 1 decade ago

    1 try high octain gas for a few tanks

    2 is car tuned up..misfire can cause it

    3 coolant full and working ok? overheaning/running hot can cause "run on"

    4 ck engine lite on..get scan [free at most parts stores]

  • 1 decade ago

    Its pre-ignition trust me or to put it in laymens terms the plug is tryining to fire when the piston is on the wrong stroke.

  • J G
    Lv 7
    1 decade ago

    Sure it's not just the ticking noise as the engine cools?

  • Sounds like it is pinking.Pre ignition.

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