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W212 Noisy Engine (OM651)

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by xAirr, Jun 21, 2017.

  1. xAirr

    xAirr New Member

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    Your Mercedes:
    E250 CDI BlueEfficiency (2009) (Engine #OM651)
    Hello.

    I have recently purchased a 2009 W212 CDI BlueEfficiency (145,000 miles) with the engine, OM651 - my first ever diesel - and noticed that it is a bit on the loud side in terms of engine noise. Having come from a silent Lexus IS250 (Petrol), it sounds like a 'bag of spanners' - even when warm.

    Any suggestions on how to make it quieter? I looked it up and saw that 2-stroke oil added into the fuel filler cap can help (alongside diesel) - is this safe? If not, what else could I do?


    Cheers!
     
  2. Craiglxviii

    Craiglxviii Senior Member

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    It is a slightly clattery engine anyway. That's what you get from a 2.2 litre turbodiesel pulling a 2 ton car.

    2 stroke oil wont do anything...
     
  3. John Laidlaw

    John Laidlaw Senior Member

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  4. Westheath

    Westheath Senior Member

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    Your Mercedes:
    Empty garage, awaiting new toy :)
    With a single duplex timing chain its a weak point on that engine, get it checked over for chain rattle.

    Also have the mileage checked on MB Star its a popular taxi vehicle.
     
  5. Headhurts

    Headhurts Senior Member

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    As others have said quite a noisy diesel but when warmed up and on the move should be much better.

    The Lexus petrol engine was always going to be much quieter.

    Did you not notice when you purchased the car?


    Sent from my iPad using Tapatalk
     
  6. kid-jensen

    kid-jensen Senior Member

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    Put more sound unsulation on the underbonnet and both sides of the bulkhead.

    Has it still got the plastic engine cover?They make a huge difference to the noise, assuming they still have the insulation attached..

    I'm sure you're detecting a theme here....diesel engines (even Mercedes ones) are noisy. The reason why some cars have quiet diesel engines is good attention to sound deadening.
     
  7. umblecumbuz

    umblecumbuz Senior Member

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    Turn the volume up!

    Umble.
     
  8. OP
    xAirr

    xAirr New Member

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    Your Mercedes:
    E250 CDI BlueEfficiency (2009) (Engine #OM651)
    Mileage was checked with gov.uk and it all adds up. Its high mileage is due to its days working as a company car, not a taxi.


    Having driven the car for about a week or so, I haven't noticed any changes after it gets warmed up - still the same 'bag of spanners,' haha.

    I knew it'd be quieter, but I hadn't thought that there'd be such a difference, having driven my brother's '08 CLS350 CDI and sister's '15 C250 CDI - both of which are much quieter in comparison. Unfortunately, I wasn't able to see the car until I had bought it.


    Yeah, the engine cover is still there. Not sure about the attached insulation though, where can I find that?
     
  9. Headhurts

    Headhurts Senior Member

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    xAirr likes this.
  10. Westheath

    Westheath Senior Member

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    Ok
    But its easy to keep mileage low by clocking before MOT or having can bus blockers fitted.

    And approx 65% of the 4 door E and S classes I have looked at over the past 2 years
    due to trying to get a straight one for my neighbour, have been tampered with mileage and service wise.
     
  11. OP
    xAirr

    xAirr New Member

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    But if they wanted to keep the mileage low, they'd have capped it at something like 80k, as opposed to letting it go until 145k, by which point it's considered a "high" mileage car.
     
  12. John Laidlaw

    John Laidlaw Senior Member

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    Insulation is on the bonnet underside
     
  13. kid-jensen

    kid-jensen Senior Member

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    .....and on the engine cover underside.
     
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  14. Mr.M

    Mr.M New Member

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    Check the engine mounts. Sometimes they may be the source of noise
     
  15. Craiglxviii

    Craiglxviii Senior Member

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    No, the engine and wheels are the sources of noise, engine mounts are NVH dampers ;)
     
  16. M80

    M80 Senior Member

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    Take it to a good Indy and ask his opinion.
    Excess noise can come from many components, there are a lot of bearings to wear on the pulley's, alternator, pumps....

    If the mileage is correct, even a fair bit higher, it should be able to run without sounding like a tractor.
     

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