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JD 6068 in Magnum 235 - turbo replaced, ran good, then rough, now will not start.

Discussion in 'Generators/Gensets' started by 03hdrk, Sep 2, 2015.

  1. 03hdrk

    03hdrk Well-Known Member

    Joined:
    Aug 29, 2015
    Messages:
    67
    Location:
    N TX
    Symptoms when brought in: runs rough, black smoke, knocking (sounded like injector not bearings), code - turbo actuator not functioning or out of calibration (don't quote me on the wording of the code.

    Work done:
    Checked turbo impeller - loose but spin. Actuator would not move. Removed turbo - aluminum pcs fell out of exh side while on the bench - then actuator started moving a little. Replaced turbo assy with factory unit (ouch $2400 at only 6000 plus hours).

    Started unit - ran normal for a about 10 seconds, but has a little black smoke. Then started running a little rough and smoke increased. Killed the engine and took a look around - no codes in the Magnum controller.
    Restarted - hard to start, lots of black smoke. After reaching RPMs knocking started and more smoke. Killed unit

    Now it will not start - no codes visible.

    Check to make sure turbo impeller moved freely - it is OK.

    Opened oil filter - no metal visible.

    Why would it run normal at first? Then go bad
     
  2. partsandservice

    partsandservice Senior Member

    Joined:
    Feb 14, 2011
    Messages:
    722
    Location:
    Georgia
    More questions ... Is it a 12 or 24 valve. Sounds like it dropped a valve. Have you removed rocker cover?
     
  3. lantraxco

    lantraxco Senior Member

    Joined:
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    Messages:
    6,684
    Location:
    Elsewhen
    Better question: What came out of the engine and jammed up the actuator in the variable turbo? Hmm? Just a guess.
     
  4. partsandservice

    partsandservice Senior Member

    Joined:
    Feb 14, 2011
    Messages:
    722
    Location:
    Georgia
    No fault codes exists for pieces of valve in turbo.
     
  5. lantraxco

    lantraxco Senior Member

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    Messages:
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    Location:
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    LOL, nor a hole in the side of the block.... oil pressure was fine as the bearing smeared the drilled hole closed, did of course cause a misfire but not enough to trip a code. I'm sure if it hadn't shaken the operator's teeth loose bad enough so he shut it down, it would have sooner or later.