clk 430 hesitation issues when accelerating

Discussion in 'Engine' started by maani, Jul 6, 2011.

  1. maani

    maani New Member

    Messages:
    28
    Joined:
    Mar 7, 2010
    Location:
    London
    Car:
    W208 clk 430 2001
    Hi All,

    I am getting a bit lost on ideas now, and would appreciate any help.
    I find the car hesitates when I put my foot down, there is a long pause then the car slowly starts picking up speed.

    I changed the MAF for original bosh part, and spark plugs were changes in Nov 2010. I also checked the live data on a star and all coil packs are in range and no issues were seen with any sensors. Also there are NO error codes stored. The emission tests at local MOT station showed no issues either.

    I have also cleaned the throttle body and idle seems to be ok, with a very slight fluctuation ever minute or so.

    Also when accelerating I do not feel the inrush of AIR like before, and not sure what values the AIR mass filter should show on the live data output.

    Has anyone had similar issues or can anyone comment on anything I have missed out or can try?

    Thanks
    maani
     
  2. BlackC55

    BlackC55 Authorised Forum Sponsor Authorised Forum Sponsor

    Messages:
    18,741
    Joined:
    Feb 8, 2007
    Location:
    Horndean, Portsmouth, Hampshire, Southsea
    Car:
    C43 AMG with a 55 engine and supercharger, E55 AMG, S500, etc
    Blocked cats?
     
  3. OP
    OP
    maani

    maani New Member

    Messages:
    28
    Joined:
    Mar 7, 2010
    Location:
    London
    Car:
    W208 clk 430 2001
    thanks BlackC55, would the emission test not show this?
    Is there a way to test if i have blocked cats?

    I have also put BG44k fuel cleaner additive.
     
  4. BlackC55

    BlackC55 Authorised Forum Sponsor Authorised Forum Sponsor

    Messages:
    18,741
    Joined:
    Feb 8, 2007
    Location:
    Horndean, Portsmouth, Hampshire, Southsea
    Car:
    C43 AMG with a 55 engine and supercharger, E55 AMG, S500, etc
    If the cats are blocked they get very very hot and often glow red.

    The value on a star for the air mass at idle is about 16 but no more for your engine.
     
  5. OP
    OP
    maani

    maani New Member

    Messages:
    28
    Joined:
    Mar 7, 2010
    Location:
    London
    Car:
    W208 clk 430 2001
    great I will recheck the air mass at idle.
    Sorry but is will this glow be visible anywhere as I am not sure how to check this?
     
  6. BlackC55

    BlackC55 Authorised Forum Sponsor Authorised Forum Sponsor

    Messages:
    18,741
    Joined:
    Feb 8, 2007
    Location:
    Horndean, Portsmouth, Hampshire, Southsea
    Car:
    C43 AMG with a 55 engine and supercharger, E55 AMG, S500, etc
    You will see the glow as it is quite obvious. Check when its dark outside.
     
  7. BlackC55

    BlackC55 Authorised Forum Sponsor Authorised Forum Sponsor

    Messages:
    18,741
    Joined:
    Feb 8, 2007
    Location:
    Horndean, Portsmouth, Hampshire, Southsea
    Car:
    C43 AMG with a 55 engine and supercharger, E55 AMG, S500, etc
    Might be worth checking fuel pressure too. You need a proper guage to do this that will fit your fuel rail. 4 bar is right from memory
     
  8. OP
    OP
    maani

    maani New Member

    Messages:
    28
    Joined:
    Mar 7, 2010
    Location:
    London
    Car:
    W208 clk 430 2001
    Thanks a lot for the great advise as always, I now have some further things to check
     
  9. OP
    OP
    maani

    maani New Member

    Messages:
    28
    Joined:
    Mar 7, 2010
    Location:
    London
    Car:
    W208 clk 430 2001
    Hi Olly,
    quick update, I took the connections to the air mass sensor off and drove the car. it felt exactly the same, also idle was no different :-(

    I am now wondering if the air mass sensor is toasted as it is a new OEM bosh part.
    On star the value was coming in as 12 on idle. Also I had a look under the car and could not see anything glowing red after I did a 5 min drive, so I hope this means the cats are ok....

    Is there any other things I can do to check if I got faulty air mass sensor, i did not by it from ebay ;-) ?

    When disconnected I started the car and also checked the voltage on the output from the top 2 connectors going in the the air mass sensor and I was seeing around 8volts, is this ok?

    Thanks
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.