1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Bumpy / Rough Idle

Discussion in 'Audi S4/A4/A4 Cab (B7 Chassis)' started by 5aq1b, Oct 28, 2012.

  1. 5aq1b
    Offline

    5aq1b Member

    Joined:
    May 27, 2010
    Messages:
    31
    Likes Received:
    1
    [Oct 28, 2012]
    hey - recently I noticed a bumpy idle which i didn't really take any notice of but over the past few weeks it's got a fair bit worse. I've got 72k on the clock so i'm due a service in around 5k miles. On a cold start it takes a couple of seconds to startup and then the rough idle begins. Usually first thing in the morning and when i've finished work. I noticed it got worse after a round trip towards Manchester which clocked up around 400 miles but i'm by no means a rough driver - especially on long journeys.

    Any ideas ??
    #1
  2. Ads

    Ads

    [Sep 17, 2014]

  3. dubdemand
    Offline

    dubdemand VAG Addict

    Joined:
    Aug 13, 2010
    Messages:
    405
    Likes Received:
    7
    [Oct 29, 2012]
    170bhp Tdi? If so that's the least of your problems...

    Our does it and I've given up trying to find a fix
    #2
  4. ctd
    Offline

    ctd Member

    Joined:
    Oct 7, 2012
    Messages:
    106
    Likes Received:
    1
    [Oct 29, 2012]
    egr valve?
    #3
  5. 5aq1b
    Offline

    5aq1b Member

    Joined:
    May 27, 2010
    Messages:
    31
    Likes Received:
    1
    [Oct 29, 2012]
    Did you also try EGR Valve? Did you get it scanned for fault codes pal?

    Would a VAG scan bring up error codes if there's not Engine management light displaying?
    #4
  6. ctd
    Offline

    ctd Member

    Joined:
    Oct 7, 2012
    Messages:
    106
    Likes Received:
    1
    [Oct 29, 2012]
    no didn't show up on diag, just had mine cleaned and the rough tick over and slight hesitation around 1800revs(not all the time) seems to have gone
    #5
  7. 5aq1b
    Offline

    5aq1b Member

    Joined:
    May 27, 2010
    Messages:
    31
    Likes Received:
    1
    [Oct 29, 2012]
    jeezo that sounds exactly like mine, I felt a slight bump at just under 2,000 revs this morning. Did you clean it yourself?
    #6
  8. ctd
    Offline

    ctd Member

    Joined:
    Oct 7, 2012
    Messages:
    106
    Likes Received:
    1
    [Oct 29, 2012]
    No local performance garage did it for 1hrs labour/£62.50, not worth getting hands dirty for that much
    #7
  9. dubdemand
    Offline

    dubdemand VAG Addict

    Joined:
    Aug 13, 2010
    Messages:
    405
    Likes Received:
    7
    [Oct 29, 2012]
    Our EGR valve looks brand new from outside and is much cleaner than the rest of the engine. I have asked my mechanic to clean it when it's been in for work in the past so assume he has done it. We still have lumpy idle and hesitation in the rev range... We also have the dreaded limp mode and no clear solution.

    Onlyfault code gives us low bost pressure and apparently there is a long list of possible components. Mechanic has suggested working through it starting with the cheapest first. Fecking car!
    #8
  10. mm707
    Offline

    mm707 Member

    Joined:
    Mar 26, 2011
    Messages:
    229
    Likes Received:
    3
    [Oct 29, 2012]
    Clean the EGR valve, take the inlet manifold off and clean all the crud from the flaps and while it's off change the vacuum actuator ( only about £10 ) as the diaphragms split inside. Did mine and it runs much better, no more hesitation or rough idling. Quite an easy job.
    #9
  11. 5aq1b
    Offline

    5aq1b Member

    Joined:
    May 27, 2010
    Messages:
    31
    Likes Received:
    1
    [Oct 29, 2012]
    Will probably give this a bash this weekend and will report back my findings, cheers for the replies so far.
    #10
  12. mm707
    Offline

    mm707 Member

    Joined:
    Mar 26, 2011
    Messages:
    229
    Likes Received:
    3
    [Oct 30, 2012]
    If you are replacing the vac unit the main dealer may not find the part number.
    It is S03G129061C

    You'll also probably need egr gasgets and inlet manifold gasgets ( less than £10 for all 3 )

    Oh and about 2 - 3 cans of carb cleaner aerosols :)
    #11
  13. 5aq1b
    Offline

    5aq1b Member

    Joined:
    May 27, 2010
    Messages:
    31
    Likes Received:
    1
    [Oct 30, 2012]
    thanks mate - should I be touching the anti shudder unit?

    Are you using ETKA by the way?
    #12
  14. purple8
    Offline

    purple8 Member

    Joined:
    Oct 12, 2012
    Messages:
    66
    Likes Received:
    0
    [Oct 30, 2012]
    I did a service on mine and new air filter improved the judder. But this is defo on my list of jobs. Once the wifes A3 is back on the road. Does it improve economy at all if so it will go higher up the list :)
    #13
  15. mm707
    Offline

    mm707 Member

    Joined:
    Mar 26, 2011
    Messages:
    229
    Likes Received:
    3
    [Oct 30, 2012]

    I got my parts from TPS , the part numbers are from their invoice, pretty sure they are ETKA - prefer to use them than main dealer.

    you need to unbolt the anti shudder unit but don't do anything with it.

    One thing to watch out for, which caught me out, is that one of the inlet manifold bolts is in the air intake and probably covered in muck so not easy to see at first.

    gasget part numbers are

    03G131547F
    069131547D
    03G129717D

    There is a good thread on here somewhere about removing the EGR, I just followed that and the inlet manifold is easy.

    The vac unit will only go on once the manifold is off and it's fairly obvious to see how it fits.
    #14
  16. 5aq1b
    Offline

    5aq1b Member

    Joined:
    May 27, 2010
    Messages:
    31
    Likes Received:
    1
    [Oct 30, 2012]
    thanks mate - what tools do i need to take these off?
    #15
  17. mm707
    Offline

    mm707 Member

    Joined:
    Mar 26, 2011
    Messages:
    229
    Likes Received:
    3
    [Oct 30, 2012]
    #16
  18. purple8
    Offline

    purple8 Member

    Joined:
    Oct 12, 2012
    Messages:
    66
    Likes Received:
    0
    [Oct 30, 2012]
    HMM Has he cleaned the inside. Or just done the scratches head whats he asking me that for and cleans the outside anyway. .. ;)
    #17
  19. mm707
    Offline

    mm707 Member

    Joined:
    Mar 26, 2011
    Messages:
    229
    Likes Received:
    3
    [Oct 30, 2012]
    What is the error code number ?
    #18

Share This Page