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Vito OM651 Alternator

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by Kev555, Oct 8, 2019.

  1. Kev555

    Kev555 Senior Member

    Messages:
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    Joined:
    Dec 31, 2017
    Location:
    Omagh NI
    Your Mercedes:
    2011 vito 113 CDI OM651 W639 panel van
    While I was fixing other things on the van over weekend I decided to try and sort out the last fault code thats been in the van from purchase 18 months ago. Its a communication fault between the starter and Alternator, OBD code is U0120. disconnected the loom running from fuse/ECU box to alternator and starter. I found no visual faults and all ends of the cables were clean and seemed to be making good connections. I disconnected the alternator last thing this eve to leave it with an autospark to be tested but for the life of me could I find a way to get it out. REALLY MERCEDES, were you that short sighted when designing the vito? After looking at the possibilitys of removing the engine mount or the radiator and possibly front of van I called it a day and thought id ask the experts on here in case ive missed an easy way out or something else?
     
    Last edited: Oct 8, 2019
  2. OP
    Kev555

    Kev555 Senior Member

    Messages:
    146
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    40
    Joined:
    Dec 31, 2017
    Location:
    Omagh NI
    Your Mercedes:
    2011 vito 113 CDI OM651 W639 panel van
    Anybody know the common cause of this fault? I have read different things on net but info is scarce on this topic, some blame loom some blame alternator voltage regulator. Dont want to make work for myself tomorrow eve if possible. Alternator is working fine and from memory its was pumping out about 14.5 volts when I tested it at the battery
     
  3. OP
    Kev555

    Kev555 Senior Member

    Messages:
    146
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    Joined:
    Dec 31, 2017
    Location:
    Omagh NI
    Your Mercedes:
    2011 vito 113 CDI OM651 W639 panel van
    Got Alternator out, studied it for a minute this eve and figured the turbo was the handiest disconnect plus would make it handy for reinstalling alternator.
    PS: just a wee note in case anybody else follows this path, make sure your exhaust is hot before you start as it will help loosen the three bolts that hold turbo to exhaust manifold as I had to use a torch to heat mine up this eve as van is non runner atm.
     
    Last edited: Oct 9, 2019
  4. OP
    Kev555

    Kev555 Senior Member

    Messages:
    146
    Likes Received:
    40
    Joined:
    Dec 31, 2017
    Location:
    Omagh NI
    Your Mercedes:
    2011 vito 113 CDI OM651 W639 panel van
    OM651.940 engine part number of turbo to manifold gasket needed for reinstalling turbo is A6510960480 (£8.50 for MB genuine on E-bay) you will also need 2 x 10mm internal diameter copper washers for the turbo oil feed pipe. I just used gasket sealer on the return oil pipe old metal gasket as its a non pressure return. Couldn't source a turbo to exhaust sealing ring handy but old one resealed ok.
     
  5. OP
    Kev555

    Kev555 Senior Member

    Messages:
    146
    Likes Received:
    40
    Joined:
    Dec 31, 2017
    Location:
    Omagh NI
    Your Mercedes:
    2011 vito 113 CDI OM651 W639 panel van
    I should have added above that the regulator on the alternator was suffering from water ingress as with a lot of bosch alternators according to the autospark. It was £50 for regulator and testing and fault code cleared. In hindsight there was a possibility of changing it while attached to the vehicle if id known exactly what the fault was?
     

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