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R170 - Possible MAF sensor problem

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by keeling54, Jan 6, 2013.

  1. keeling54

    keeling54 Active Member

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    Your Mercedes:
    SLK/1999/2300
    Guys,

    Am I right to suspect a MAF sensor problem with the following symptoms...

    - Totally lack of power
    - No kick down
    - Engine won't rev past around 4000rpm in any gear.
    - Occasional stutter when accelerating.

    The car is a 1999 SLK 230 with 150k miles on the clock. I removed and cleaned the sensor and things didn't improve very much although the stuttering did reduce.

    I have ordered a new Bosch one from euro car parts that should arrive in a couple of days.

    If this doesn't cure it what else could it be.
     
    Last edited: Jan 6, 2013
  2. television

    television Always remembered RIP

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    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    As you have the 11 engine do pull the camshaft sensor plug off top center front of engine and check for any oil,,if there is get the CAM magnet blocker from Mercedes.

    It does sound like you MAF
     
  3. OP
    keeling54

    keeling54 Active Member

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    Is the cam magnet an expensive part. Can they be sourced from anywhere other than MB.
     
  4. television

    television Always remembered RIP

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    £30 but only if the plug has oil inside it, if it is leaking the oil will go into the engine wiring harness, and then it starts getting expensive
     
  5. OP
    keeling54

    keeling54 Active Member

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    I'll take a look tomorrow thanks.

    Is it visible without removing any shrouding or does the cam cover need to come off.
     
  6. television

    television Always remembered RIP

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    You should be able to see it without removing anything
     
  7. Alex Crow

    Alex Crow Senior Member

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    Your Mercedes:
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    This car is too old for the cam magnet blocker.
    Yes, it does sound like a MAF sensor though, but an expensive guess!
     
  8. OP
    keeling54

    keeling54 Active Member

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    Just to close this out, I received and fitted a new MAF sensor tonight and the problems solved, the car drives like a dream now. Completely fixed.

    I bought an original Bosch unit from Euro Car Parts via their ebay shop. £126 all in, the cheapest I could find.

    I also checked the cam magnet and although covered in oil, it hadn't migrated up the cable. It's the round pin type so the blocker won't fit.

    I did see a solution on another forum where they suggested stripping back the insulation on each cable and soldering the individual strands of each cable together, thereby blocking the oil path. I may have a go at this at the weekend.

    Anyway thanks again for the advice.
     
  9. television

    television Always remembered RIP

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    I know that some members just cringe when I have said the MAF without testing, but in 95% of the time it fixes it
     
  10. OP
    keeling54

    keeling54 Active Member

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    Having checked other web sites and forums everything pointed to the MAF, plus that fact i could try it without wasting time and money at a garage.
     
  11. jibcl500

    jibcl500 Senior Member

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    Your Mercedes:
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    got a used maf in stock if you want one.

    jib
     

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