W124 300e - petrol fumes

Discussion in 'Engine' started by theRéhann, Mar 13, 2015.

  1. theRéhann

    theRéhann New Member

    Messages:
    10
    Joined:
    Mar 10, 2015
    Location:
    Johannesburg, South Africa
    Car:
    '91 W124 300e and 2011 Triumph Tiger Explorer
    I have a fair idea that this problem is being caused by blocked breathers somewhere, but expert advice would be greatly appreciated...

    The car runs fine, but intermittently, mostly after driving for quite a while, you can smell petrol fumes. When you open the fuel filler cap, there is a "whoosh" sound, showing a vacuum being formed in the tank.

    Would I be able to clean the breathers, wherever they are?
    Is it just a cleaning job, or is this major surgery?

    The car has done 230 000 kms (142 000 miles), so I'm not to surprised about the amount of attention the car needs.

    Any expert advice most welcome!
    469
     
  2. Bellow

    Bellow MB Enthusiast

    Messages:
    5,849
    Joined:
    Apr 26, 2010
    Location:
    Ecosse.
    Car:
    450
    If your car is thus configured, this may help.

    [​IMG]
     
    Last edited: Mar 13, 2015
  3. OP
    OP
    theRéhann

    theRéhann New Member

    Messages:
    10
    Joined:
    Mar 10, 2015
    Location:
    Johannesburg, South Africa
    Car:
    '91 W124 300e and 2011 Triumph Tiger Explorer
    Thanks, I have seen that graphic.

    With my limited technical knowledge, I am thinking the lines at number 4 must be the culprits?





    1369
     
  4. hotrodder

    hotrodder Active Member

    Messages:
    845
    Joined:
    Sep 28, 2008
    Location:
    south east
    Car:
    '93 320te
    A 'whoosh' when the filler cap is removed is normal. 47 Fuel system - M103 47-0030 goes into a bit more depth about the tank venting system, while 50 mbar (~0.725 psig) doesn't sound like much that's the equivilant of around 30 litres of air escaping if a 70 litre tank has 10 litres of fuel left in it when the cap is removed...

    The diaphragm (#4) is less of a suspect than a blocked charcoal canister or a leak in one of the evap hoses (or a leak elsewhere) imo. The charcoal canister isn't servicable, they are scheduled to be replaced once in a blue moon (every 72k miles/4 years according to the service book for my 320) but often aren't as they're tucked away behind the wheel arch liner inbetween the inner & outer wing and usually last a lot longer than the service schedule suggests. They cost around £50 but obviously won't fix things if the problem is a leak at one of the hose connections anywhere in the fuel and/or tank venting system etc
     
    Last edited: Mar 13, 2015
  5. OP
    OP
    theRéhann

    theRéhann New Member

    Messages:
    10
    Joined:
    Mar 10, 2015
    Location:
    Johannesburg, South Africa
    Car:
    '91 W124 300e and 2011 Triumph Tiger Explorer
    Thank you very much, I appreciate the advice!



    194
     
  6. OP
    OP
    theRéhann

    theRéhann New Member

    Messages:
    10
    Joined:
    Mar 10, 2015
    Location:
    Johannesburg, South Africa
    Car:
    '91 W124 300e and 2011 Triumph Tiger Explorer
    Update: It seems like the problem is actually related to worn injectors that leak.

    I should've known better, because the car does "flood" after a short trip...

    Got a quote from an independent workshop specialising in Benz for replacement of all six injectors, seals, labour etc for ZAR6 500 (about GBP360).

    How does that compare to what you would pay in the UK?






    211
     
  7. ray_hennig

    ray_hennig Active Member

    Messages:
    611
    Joined:
    Dec 1, 2008
    Location:
    France
    Car:
    MB 300CE-24 Sportline
    The injectors for yours are about £30 each, unless you have the M104 twin cam engine, in which case they're about double that. Seals and guides maybe another £50 making something like £230 to do it yourself.

    I did this job recently on the M104 and it was well worthwhile. However, there was never any fuel smell - any leakage was internal and burnt off on start-up.

    Have you checked the EHA on the fuel distributor? These are notorious for leaks, either the grommets (very cheap) or the EHA itself (not very cheap). Worth checking perhaps.

    Good luck.

    RayH
     
  8. anfieldassasin

    anfieldassasin Active Member

    Messages:
    267
    Joined:
    Nov 23, 2014
    Location:
    Essex
    Car:
    1988 300ce, E46 323ci, 1990 230ce C124 (sold), cl203 180k (other half)
    Hey might not be useful but in my 1990 230ce m102 engine, I had the same problem. Start with the simple things, for me this was the fuel filter leaking at the back which still caused a strong smell of fuel in the car, also as has already been suggested the EHA valve can leak either through worn o-rings (cheap fix) or the valve body it's self being cracked (expensive fix), in my case the screws holding it to the fuel distributor were loose!

    I changed the 4 injectors on my m102 took about 30mins, original bosch injectors were £22 each plus seals were £1-2 each (from germany, pm me if you want the website address unless I'm allowed to post it here). The 300e is an m103 right?? Why not have a go at replacing them your self?

    Bw
    Sam
     

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