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Why is my rpm jumpy

Discussion in 'A3/S3/Sportback (8P Chassis)' started by HenrikMeister, Aug 27, 2013.

  1. HenrikMeister
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    HenrikMeister Member

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    [Aug 27, 2013]
    Jumpy rpm needle audi a3 8p - YouTube
    Tried cleaning the throttle body, maf sensor, changing the spark plugs, cleaning the engine. But the problem stil occurs. Any idea on this guys? Possibly a vacuum leak? If so, where is the first thing I should look?
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  3. s900029
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    s900029 New Member

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  4. MrLapou
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    MrLapou Well-Known Member

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    [Aug 27, 2013]
    With a warm engine, try removing the oil filler cap while car idles to see if that makes a difference. In a normal engine, it'll make revs fall and rise.
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  5. HenrikMeister
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    [Aug 27, 2013]
    Warm engine, coolant at 90 degrees. Removed the oil cap, no noticable differnce. Engine shaking just slighrly but not that much when removed. Tried with the dipstick, no signs of difference
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  6. MrLapou
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    MrLapou Well-Known Member

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    [Aug 27, 2013]
    Ok. then it points to a vacuum leak.

    Do you have access to VCDS or a blue tooth OBD2 dongle plus Android phone running Torque?
    Thay way vacuum can be monitored.
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  7. HenrikMeister
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    HenrikMeister Member

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    [Aug 27, 2013]
    I have a CAN obd2, i can diagnos a car but cant write. What parameter should i look at mate?
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  8. HenrikMeister
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    [Jun 6, 2014]
    Sorry, but need to bring this thread to life, as i am still having the problem.
    Well i now have access to vcds. I assume i am going to engine 01 > then? :)
    I also tried removing the pcv valve from the engine block itself. I then started the engine. Rpm raises about 2000rpm then back to 777 RPM then back to 2k RPM. Needle was still jumpy when that was removed. Any more ideas?
    I only have a NOX sensor fault in vcds. But that might not be the problem?
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  9. HenrikMeister
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    [Jun 6, 2014]
    Engine is also "choking" in idle. After driving the car an hour or two. Here is a video of ot choking
    http://youtu.be/4iWFxE1AnVk

    When its choking. It does this every 30-ish second...
    #8
  10. wuta3
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    wuta3 Well-Known Member

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    [Jun 6, 2014]
    Holy thread revival. Sounds like PCV failure if its a lumpy idle with hunting revs.
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  11. HenrikMeister
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    [Jun 7, 2014]
    What i thought too. I dont think it is the pcv. Removing it will not remove the jumpy needle issue. But after researching, the EGR (exhaust gas recirculation) unite might need to be cleaned. The EGR is located right beside/behind the throttle body. It contains gears that maybe broke (cheap plastic gear) or just clogged up. Will check on this tomorrow or sunday. They say that it is a simple process looking at this. Will give feedback on this!
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  12. HenrikMeister
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    [Jun 7, 2014]
    [​IMG]

    Here is the egr valve btw
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  13. RedDejavu
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    RedDejavu Well-Known Member

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    [Jun 7, 2014]
    check the DV mate for any splits
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  14. HenrikMeister
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    HenrikMeister Member

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    [Jun 7, 2014]
    You mean the diverter right? Dont have it, as my engine is N/A
    Last edited: Jun 7, 2014
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  15. RedDejavu
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    RedDejavu Well-Known Member

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    [Jun 7, 2014]
    ahh ok you didnt state what engine it is:)
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  16. HenrikMeister
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    [Jun 7, 2014]
    Upps, my mistake then!
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  17. HenrikMeister
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    [Jun 7, 2014]
    Update: removing just the connector didnt make any change
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  18. HenrikMeister
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    [Jun 7, 2014]
    Update 2: removed the top lid on the egr. Lots of dirt, cleaned it. No change.
    Tried removing the 4 T-30 screws. But ended up with stripping the torx bit in half. No more updates.
    [​IMG]
    Last edited: Jun 7, 2014
    #17

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