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

Sudden poor mpg c220 diesel estate

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by streaker, Nov 4, 2012.

  1. streaker

    streaker Active Member

    Messages:
    42
    Likes Received:
    0
    Joined:
    Nov 4, 2012
    Location:
    Somerset
    Your Mercedes:
    C220 Estate 2004 2.2 Diesel
    Hello Forum

    My first post and my first mercedes

    I bought my car 4 weeks ago, Facelift c220 diesel auto estate full MB service history, and so far very happy, although there are a few things that need sorting but its done 99k.
    It has been returning about 42 mpg combined, I commute from Somerset to Liverpool weekly and then its short (5 miles) to and from work,
    However on the trip home on friday night I struggled to get 25 mpg, speed made very little difference 50 to 90 mph only 2 or 3 mpg difference according to the computer, filling up today confirmed i used £48 of diesel to do 195 miles.

    Today I serviced the car replacing all the filters and the thermostat ( it was taking 10 - 15 miles to reach 80c) but no improvement in mpg, until i disconnected the MAF immediately the mpg went back up to low 40's (10 miles of A and B roads)

    when I bought the car the dealer ( not mercedes ) told me the DPF had been deleted from the map and the internals had been removed, I've no reason to doubt this as i believe the remap has also increased the power over the other c220's i test drove

    The car has been producing a lot of black smoke on acceleration, and on kick down its embarrassing but it pulls like a train so i thought the smoke was a result of the remap, now the MAF is disconnected the powers slightly down but the black smoke has virtually gone.

    So I guess I'm going to need a new MAF ?, but my real question is, am I ok to keep the MAF disconnected until I fit the new MAF ?

    Many Thanks for any advice you can give

    Adam
     
  2. mr mercedes knowledge

    mr mercedes knowledge Active Member

    Messages:
    29
    Likes Received:
    0
    Joined:
    May 14, 2012
    Your Mercedes:
    E63 amg
    A new air mass is £60, best to change it
     
  3. ernieh

    ernieh Senior Member

    Messages:
    1,425
    Likes Received:
    65
    Joined:
    Nov 20, 2006
    Location:
    Scotland, East
    Your Mercedes:
    205 / 67 / C220 d
    ....but don't buy a cheapscate one from the internet; best go to a Bosch Service agent,or pay over-the-odds from MB!


    Ernie
     
  4. grober

    grober Senior Member

    Messages:
    2,935
    Likes Received:
    21
    Joined:
    May 15, 2002
    Location:
    Scotland
    Your Mercedes:
    W204 C200cdi estate
    When you disconnect the MAF the engine ECU defaults to a "one size fits all" map which ignores several sensors and this is possibly different to the " remap" which would explain the change in power/ fuelling. Won't do any harm but I would resist the temptation to "cane it" until you get the new MAF fitted.
     
  5. OP
    streaker

    streaker Active Member

    Messages:
    42
    Likes Received:
    0
    Joined:
    Nov 4, 2012
    Location:
    Somerset
    Your Mercedes:
    C220 Estate 2004 2.2 Diesel
    Thanks for the responses guys

    Yes I will be ordering a Bosch MAF today, now just got to figure out how to get the heating to work and the rear wiper and ill be a happy motorist
     

Share This Page