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

Engine idle rough, white smoke and vibration

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by Darren Ritchie, Nov 14, 2019.

  1. Darren Ritchie

    Darren Ritchie New Member

    Messages:
    4
    Likes Received:
    1
    Joined:
    Nov 14, 2019
    Location:
    West Lothian
    Your Mercedes:
    ML320 w164 om642
    My ML320 2007 W164 CDI om642 has a very rough idle and produces a lot of white smoke. Car takes around 4 seconds of turning before it starts.

    There does not seem to be any coolant being used

    The idle clears up if you rev it above 2.5k rpm (still smoky though)

    Computer reads a misfire in cylinder 3, tried swapping that injector over, made no difference.

    If I pull the plug from Injector 3, would this stop the smoke and maybe prove its that injector.

    Does a previously used injector need coded.

    Any help appreciated

    I can see a couple posts with almost exact same issue, bit no one ever come back to say the fix

    Thanks again

    Darren
     
  2. M80

    M80 Senior Member

    Messages:
    3,443
    Likes Received:
    649
    Joined:
    Jan 21, 2006
    Location:
    Derbyshire
    Your Mercedes:
    Vito 115 Lwb Dualiner.
    Yes, pretty sure the injector would want coding.
    They aren't repairable either, apparently, being Piezo.

    I would be cautious disabling a cylinder, especiallly any end cyclinder. The imbalance on the crank would put strain on the big end bearings.

    Some years ago I took out a 4cyl engine within 12 miles running it a cylinder down to get home.
     
    Darren Ritchie likes this.
  3. Larkone

    Larkone Senior Member

    Messages:
    259
    Likes Received:
    128
    Joined:
    Aug 19, 2016
    Location:
    NW Essex
    Your Mercedes:
    CLS 320CDI 2008
    White smoke:

    White smoke is caused by raw, un-burnt fuel passing into the exhaust stream. Common causes include:
    · Incorrect fuel injection timing
    · Defective fuel injectors
    · Low cylinder compression

    Low cylinder compression may be caused by leaking valves, sticking piston rings, ring wear, cylinder wear, or cylinder glaze. When white smoke occurs at cold start and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing.
    Continuous evidence of white smoke indicates a mechanical defect, or incorrect fuel timing.
     
    gassed up likes this.
  4. OP
    Darren Ritchie

    Darren Ritchie New Member

    Messages:
    4
    Likes Received:
    1
    Joined:
    Nov 14, 2019
    Location:
    West Lothian
    Your Mercedes:
    ML320 w164 om642
    Yeah I found that post already. I'm just hoping that someone somewhere has had the same thing happen to their car. I'm going to assume I will needs the injector coded now before moving onto any other possible cause.

    Maybe do my own little compression test at the weekend just for peace of mind.

    Any other ideas or anyone has similar, please let me know. Would love ther car on the road asap.

    Thanks
     
  5. hamodi

    hamodi Member

    Messages:
    12
    Likes Received:
    0
    Joined:
    May 22, 2016
    Your Mercedes:
    W221 2007 S320L CDI
    Hi, did you get anywhere with this? Experiencing the same problem after changing high pressure diesel pump.
     
  6. OP
    Darren Ritchie

    Darren Ritchie New Member

    Messages:
    4
    Likes Received:
    1
    Joined:
    Nov 14, 2019
    Location:
    West Lothian
    Your Mercedes:
    ML320 w164 om642
    I'm literally half way through stripping the head off. Might not be the issue but snapped a glow plug and also wanted to change the oil cooler seals and glow plug module. I'll keep you posted.
     
    d215yq likes this.
  7. Kev555

    Kev555 Senior Member

    Messages:
    248
    Likes Received:
    117
    Joined:
    Dec 31, 2017
    Location:
    N.I
    Your Mercedes:
    2011 vito 113 CDI OM651 W639 panel van
    As I was told by a few wise heads on here at the start of the year after having a similar problem start with the basics. Fuel pressures, low pressure tank pump if your vehicle has one then High pressure pump. After that compression test then start to look at injectors. If you have a icarsoft reader it should tell you the low and high pump pressures. Mine was an injector problem and they were Delphi. My problem does sound very similar to yours with cylinder three always showing up as the problem even when swapping injectors
     
  8. alexanderfoti

    alexanderfoti MBO Forum Supporter Authorised Forum Supporter

    Messages:
    11,771
    Likes Received:
    2,114
    Joined:
    Mar 25, 2010
    Location:
    Tonbridge
    Your Mercedes:
    W221 S65 AMG - W204 C63 AMG + Various other MB's
    Turn off the injector on no3 (via diag) and see if the smoke stops.

    If it does, either injector spray pattern, or low compression on that cylinder. You can test the relative compression on that cylinder with diag, or use a traditional diesel comp tester.
     
    Kev555 likes this.
  9. OP
    Darren Ritchie

    Darren Ritchie New Member

    Messages:
    4
    Likes Received:
    1
    Joined:
    Nov 14, 2019
    Location:
    West Lothian
    Your Mercedes:
    ML320 w164 om642
    I snapped a glow plug so I'm all the way down and about to pull the head this weekend. (Off the car that is)

    Doing the oil cooler seals etc while there.

    U can clearly see all 5 inlet ports are carbon and cylinder 3 is very clean, so fuel has been around unburned that's for sure.

    I'll keep you posted by Monday the 9th December what the issue was or may have been.

    Not looking FWD to the rebuild. Not at all
     
  10. ajlsl600

    ajlsl600 Senior Member

    Messages:
    3,450
    Likes Received:
    1,291
    Joined:
    Nov 18, 2013
    Location:
    france
    Your Mercedes:
    clk3202001,sl6002003 with everything,A class 170cdi auto
    for me, after a quick look around for something simple the basics .would be a compression test FIRST if thats not right nothing is going to get better. then ,injector issues. as ,fuel press unlikely to effect 1 cly.
     
    Kev555 likes this.
  11. ajlsl600

    ajlsl600 Senior Member

    Messages:
    3,450
    Likes Received:
    1,291
    Joined:
    Nov 18, 2013
    Location:
    france
    Your Mercedes:
    clk3202001,sl6002003 with everything,A class 170cdi auto
    DONT be in a hurry and likely you will be fine , if yr not expeienced run thru the process 4 5 times in yr head before starting
     
    Kev555 likes this.

Share This Page