R129 500SL Engine question

Discussion in 'Engine' started by rocketfixer, Apr 3, 2014.

  1. rocketfixer

    rocketfixer New Member

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    Reading many of the serious Engine misfire problems on the Forum, makes mine sound a little pathetic, but worth bringing up.

    Car is R129 500SL, year 2000, 113 eng.
    It has a very slight rough idle. Not sure if these engines should be silky smooth... Should I be able to put a Martini on the eng cover and have it not shaken or stirred??
    Anyway, I was doing some general trouble shooting - running the car on the drive and I increase the revs, I get to about 4200 rpm and it starts serious hunting and very lumpy.
    Is a rev limiter kicking in,,, because when normal driving it really flies and will rev to the redline with ease.... pretty impressive.
    Many thanks for any input.
     
  2. Sp!ke

    Sp!ke Administrator Staff Member

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    It wont let you rev fully in neutral by design.
     
  3. c63chris

    c63chris Hardcore MB Enthusiast

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    What Spike says, it limits the revs under no load to protect the engine.
     
  4. Grey Area

    Grey Area Hardcore MB Enthusiast

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    I have the same problem on my c230k, the idle is just slightly lumpy and uneven, I suspect mine is the cheap MAF the guy who sold it to me put on it. But an old one might cause the same symptoms, maybe?
     
  5. John Jones Jr

    John Jones Jr Hardcore MB Enthusiast

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    Don't mess about just get a new Bosch or Pierburg MAF. EBay.de is your friend.
     
  6. Sp!ke

    Sp!ke Administrator Staff Member

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    ebay mafs are often cheap clones though I thought.

    I would get it on a star to look for error codes first before spending money on anything.
     
  7. OP
    OP
    rocketfixer

    rocketfixer New Member

    Messages:
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    Engine replys

    Many thanks to all... particularly to Sp!ke and c63chris. I thought this could well be the case, but I have never come across this before. Thanks for setting my mind to rest.
    Cheers.
     
  8. rorf

    rorf Hardcore MB Enthusiast

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    Car:
    2000 SL320 v6, 2001 CLK320
    Could even be your engine mounts on their way out. What is the mileage on your car?
     
  9. Grey Area

    Grey Area Hardcore MB Enthusiast

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    How would the engine mounts cause an uneven idle? I don't mean that impertinently, I'm genuinely curious.
    @jjj I don't know for sure that mine is a cheap one, I'm just assuming. The seller didn't seem the type to shell out for genuine MB parts.
     
  10. Sp!ke

    Sp!ke Administrator Staff Member

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    If the engine mounts are past their best they may not damp the engine as well as they should and cause vibrations to be felt in the cabin.

    On tickover, once warm, does the engine miss at all?
     
  11. rorf

    rorf Hardcore MB Enthusiast

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    He said his engine had a rough idle - not a misfire:rolleyes:

    A very common problem with M113 and M112 engines.
     
    Last edited: Apr 4, 2014

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