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Thread: MAF sensor replacement

  1. #1
    Team Z8 ZMates's Avatar
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    MAF sensor replacement

    for what it's worth...

    I still have the original MAF sensors in my car. I got an OBDII code related to the sensors just a few days before I had to bring the car in for an inspection...no time to order replacements, so I cleaned the sensors with alcohol. The improvement in power and rpm stability was remarkable and no error code. Alas after a couple weeks it's back to running lean and the error code has returned. No idea why cleaning gives only a temporary improvement, but my advice is don't bother cleaning, just order new ones:

    http://www.bimmerzone.com/product/BIM-E39M5-MAFS.html
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    Dinan S2 package: headers, throttle bodies, oversized MAFs, airfilters, anti-roll bars, lightweight flywheel
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    Quaife differential, 3.64:1 final drive
    Meisterschaft GT titanium mufflers
    K&W 3 way adjustable competition monotube dampers and monoball adjustable mounts
    CDV delete

  2. #2
    I've read this before on the M5 Board too, so it does seem to be the case.
    Andrew Macpherson

    Expert Z8 Inspections, with full support for both Z8 sale and purchases.

  3. #3
    Z8Mania
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    Yes, a cleaning can get you a temporary fix but after a while you really just have to replace them.

  4. #4
    DSC Off JohnAnthony's Avatar
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    the mafs will fail long before you even get a code for them

    i'm not sure if you can unlock your obc menu like on other bmws but there is a test to measure fuel in ltr/hour consumed which you can use to determine if your mafs are working optimally (given nothing else is wrong)

    http://www.youtube.com/watch?v=cXrWrkEqClU

    best way is to replace them at certain intervals or get a maf-less tune which you can go back and forth with by plugging the mafs back in when you want

  5. #5
    Team Z8 ZMates's Avatar
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    looks like I was a little too hasty. I installed the new MAF sensors and the engine still ran rough. I checked the OBDII code and it was the Cam Position Sensor making the problem, not the MAF sensors.
    Silver/black
    Dinan S2 package: headers, throttle bodies, oversized MAFs, airfilters, anti-roll bars, lightweight flywheel
    Dinan by Brembo brake kit and monoball control arm bushings
    BBS forged individual wheels
    Quaife differential, 3.64:1 final drive
    Meisterschaft GT titanium mufflers
    K&W 3 way adjustable competition monotube dampers and monoball adjustable mounts
    CDV delete

  6. #6
    Z8Mania
    Guest
    I guess you'll still have the benefit of new & clean MAF sensors. Sorry to hear of the CAM sensor. That seems like a malady that will affect us all at some point.

  7. #7
    Team Z8 ZMates's Avatar
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    Both driver side CPS's replaced. Rifle's suggestion to remove the baffle (two easily reached screws) really helped. Took 30 minutes this time, but 10 if I had to do it again.

    Rifle suggests going at the passenger side CPS's from below. Hope my arms are long enough.
    Silver/black
    Dinan S2 package: headers, throttle bodies, oversized MAFs, airfilters, anti-roll bars, lightweight flywheel
    Dinan by Brembo brake kit and monoball control arm bushings
    BBS forged individual wheels
    Quaife differential, 3.64:1 final drive
    Meisterschaft GT titanium mufflers
    K&W 3 way adjustable competition monotube dampers and monoball adjustable mounts
    CDV delete

  8. #8
    Administrator thegunguy's Avatar
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    Do some yoga first.

    Glad my tips helped. I'm planning to replace my MAFs in the next month or so too.
    thegunguy

  9. #9
    Z8 Ate My Homework! Norcal's Avatar
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    I'm going to have my MAFs replaced too. I just dropped my car at Peter Pan for the cold-start issue.

  10. #10
    Team Z8 ZMates's Avatar
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    Quote Originally Posted by thegunguy View Post
    Do some yoga first.
    I just hope the Dinan headers help, not hinder, the operation. I really don't see a convenient way in from the top.
    Silver/black
    Dinan S2 package: headers, throttle bodies, oversized MAFs, airfilters, anti-roll bars, lightweight flywheel
    Dinan by Brembo brake kit and monoball control arm bushings
    BBS forged individual wheels
    Quaife differential, 3.64:1 final drive
    Meisterschaft GT titanium mufflers
    K&W 3 way adjustable competition monotube dampers and monoball adjustable mounts
    CDV delete

  11. #11
    Administrator thegunguy's Avatar
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    Knowing the history of the Dinan headers, I'm going to guess that they take up more room. You might need to find a lanky supermodel to fit their arm up to the CPS.
    thegunguy

  12. #12
    Team Z8 ZMates's Avatar
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    Quote Originally Posted by thegunguy View Post
    You might need to find a lanky supermodel to fit their arm up to the CPS.
    Know where I can find one? I managed to replace the exhaust sensor, but no way to get to the intake. I think I'm going to have to start removing parts and have a go from the top.
    Silver/black
    Dinan S2 package: headers, throttle bodies, oversized MAFs, airfilters, anti-roll bars, lightweight flywheel
    Dinan by Brembo brake kit and monoball control arm bushings
    BBS forged individual wheels
    Quaife differential, 3.64:1 final drive
    Meisterschaft GT titanium mufflers
    K&W 3 way adjustable competition monotube dampers and monoball adjustable mounts
    CDV delete

  13. #13
    Administrator thegunguy's Avatar
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    The intake one is tough. If you come up with a good method, let us know. The harness seems to be the main obstruction.
    thegunguy