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Help please ML 270 cdi black smoking really bad

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by omegav6, Jul 24, 2009.

  1. omegav6

    omegav6 Active Member

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    Hi all I’m wondering if someone can give me advice on what to try next, I’m getting frustrated with this now the car is smoking thick black smoke when you put your foot down hard and it doesn’t stop when you let your foot off a bit. If you was three cars behind me you would think it had gone dark it’s that bad, the performance don’t seem that bad but i don’t drive the car that much the Mrs drives it. I’ve tried giving it a good long hard run to clear it to no avail. The injectors have been re seated and new bolts and washers used, all filters are new and the maf has been cleaned. The car has covered 100k which i don’t believe is a lot for this engine. Any help or advice on what to try next will be greatly received
    I would also like to thank Kebo57 for all his help with the other problems ive had with the car
     
    Last edited: Jul 24, 2009
  2. 5pares

    5pares Senior Member

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    Your Mercedes:
    E320cdi
    Could be a turbo problem if youve check all the simple stuff,hoses, injectors etc.
     
  3. OP
    omegav6

    omegav6 Active Member

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    The turbo seems to be working fine and when the injectors where re seated they looked in vgc thanks for the reply
     
  4. teddycatkin

    teddycatkin Senior Member

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    Your Mercedes:
    W107-SL W124-220te W123-230e W201 2.0
    Usually Turbo blown ?--the smoke will be oil in the exhaust.
    Needs a diagnostic plug in to confirm the problem.
     
  5. BlackC55

    BlackC55 Senior Member

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    C43
    I suspect a split boost pipe or intercooler.
     
  6. OP
    omegav6

    omegav6 Active Member

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    ive always thought that engine oil smoke was blue ish and derv smoke was black am i wrong in thinking this
     
  7. star

    star Forum Supporter Authorised Forum Supporter

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    Smart + others :)
    +1, and they do take some clearing if pottered around.
     
  8. OP
    omegav6

    omegav6 Active Member

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    it don't really potter around she does drive it hard but its all town work no m ways its had a good 150mile m way run now and problem still there ive just spoke to a fried of mine and hes give me a number for someone who has a machine to plug into the car and see if there is anything showing up but there have been no lights on on thes dash will this matter
     
  9. stumo

    stumo Senior Member

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    Your Mercedes:
    ML270CDI 2002 facelift| Sprinter 316CDI 2003 LWB
    I reckon I know what it is...

    I forget the technical term for them, but this engine has these flaps in the inlet manifold, they are there to help with engine braking etc. They are driven electronically, and they have been known to fail.
     
  10. oigle

    oigle Senior Member

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    Your Mercedes:
    Currently 2003 ML270. 2012 Nissan Maxima 250SL.
    You said you had cleaned your MAF. That doesn't mean it is OK. It is the main article that gives you your air/fuel mixture. I'd be inclined to check it properly.
     
  11. Alex Crow

    Alex Crow Senior Member Authorised Forum Supporter

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    Your Mercedes:
    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    lots of possibilities here. the black smoke will be excess fuel, ie too much fuel for the oxygen available for combustion. possibly a leaking intercooler, intake hose, intake manifold (at flaps) or sticking egr valve loosing boost pressure. many other likely scenarios though but leaks and sticking egr are easiest to check. also how about that air filter ;). any hissing noticed?

    not likely to be failed turbo though, generally fairly solid on the 611, 612 and 613 motors.
     
  12. OP
    omegav6

    omegav6 Active Member

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    i have had the codes read a friend of mine took it whilst i was at work there was a few things stored only 2 that cold mean anything, 1st was the maf 2nd egr don't know what the codes where but i have had the maf unplugged and drove the car to see if there was any change which didn't.As i have said before i have cleaned it but don.t know the correct way to check it as for the egr this has not been looked at something to do next week now. i have noticed no hissing at all
     
  13. star

    star Forum Supporter Authorised Forum Supporter

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    an egr fault will also make a maf fault show.
     
  14. Alex Crow

    Alex Crow Senior Member Authorised Forum Supporter

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    Your Mercedes:
    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    quite right. to check for egr sticking, disconnect the vacuum pipe and tap enthusiastically with a hammer many times - then go for a run, not foolproof but without the das and techy a good starting point.
     
  15. clive-cls

    clive-cls Banned

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    Yes a friend of mine had a faulty MAF causing smoke problems. But if you unplugged it and it didn't make a difference it sounds like it could also be a fault with your EGR valve or maybe overfuelling? I'd maybe get a garage or Mercedes to run diagnostics through to check it out before it gets worse.

    Clive
     
    Last edited: Aug 1, 2009
  16. Mark A

    Mark A Senior Member

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    Your Mercedes:
    08 ML-420CDI, 58 ML-320CDI, 55 SLK-350
    The wife's ML-270 had a similar problem, I tried disconecting the MAF and it made no difference. Bit the bullet, bought a new MAF and hey presto back to normal again. The disconnecting the MAF trick doesn't always work, and a new MAF is only 1/2 the price of an EGR.

    Mark
     
  17. OP
    omegav6

    omegav6 Active Member

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    hi all i have tonight took off the egr and its very very clogged up to say the least thick black gunk. I have cleaned it all out and it now looks clean and ready to be put back on is there a way to test the egr to see if its working correctly i don't really know what the part does also do you think this could be my problem with the b;ack smoke
    cheers for all the input on this one guys
     
  18. Alex Crow

    Alex Crow Senior Member Authorised Forum Supporter

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    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    although the egr is not usually problematic on ml270s
     
  19. OP
    omegav6

    omegav6 Active Member

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    when vacuum is applied does anything move inside the egr that you can see eg the bar that goes across the egr as you look inside it
     
  20. Alex Crow

    Alex Crow Senior Member Authorised Forum Supporter

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    Your Mercedes:
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    if you take the hose off and look inside you might be able to see the mechanism move under vacuum, you should hear it snap back when vacuum is removed, even so it`s hard to check for it sticking under driving conditions. i have known a couple of broken diaphragms on 320 engines which caused all sorts of mischief, ie crud getting into the vacuum circuit and blocking the vacuum feed (or is it return?? all goes backwards with vacuum!). so check it holds vacuum too..........
     

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