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Won't rev when cold ? Turbo, swirl flap or back pressure sensor

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by AMck, Aug 6, 2018.

  1. AMck

    AMck Senior Member

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    Your Mercedes:
    2007 E320cdi S211, SL320 2000(written off), 2007,Volvo C70 D5, 1976 Ford Gran Torino, 1978 VW camper
    I've been having a few issues with my E320cdi with V6 OM642 lately.

    It started with a loss of power and slow to build up revs, but I could drive round it by using manual gear change and keeping revs around 2500. This felt as if turbo not working and confirmed by watching actuator, but if I restarted engine the actuator would test ok. At this point I was getting code
    2510-091 check component Y77/1

    After a few more journeys I then also had code

    2616-002 check component B60(exhaust back pressure sensor). Control variation - exhaust back pressure is too high

    When testing either of these components via STAR, both checked out ok.

    I reset codes and drove for a few days. It then drove better once warm, but when cold it wouldn't rev over 1500rpm. I then got codes

    2513-001 check component M55 (inlet port shutoff motor) positioner signals fault and
    2510-001 as above

    I checked inlet port shutoff motor and this tested as not ok on STAR. From info on here I found it was possible to bypass inlet shutoff with a 4.7kohm resistor. I did this and on STAR it now tests as OK, but I still have the same issue of the engine not revving over 1500 rpm when cold. Also the only code I am now getting is 2616-002 check component B60(exhaust back pressure sensor). Control variation - exhaust back pressure is too high.
    It also seems to be running rich, both by smell and very sooty exhausts. I'm also pretty sure I do not have a dpf fitted as I don't have code SA code 474, so that can't be giving back pressure.

    So, my question is, is this likely to be the turbo as this was the first code I had, or the swirl flaps as I've bypassed them or the just the back pressure sensor ( which checks ok on STAR ), or a combination.

    Any help appreciated before I spend money replacing parts.
     
  2. onefortheroad

    onefortheroad Senior Member

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    Can you get live data from the ebps ? And what pressure its seeing
     
  3. Botus

    Botus Senior Member

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    Your Mercedes:
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    remove engine cover
    start engine
    blip throttle repeatedly
    look to see if turbo actuator moves back and forth

    if no movement
    disconnect swirl flap motor and fit 9 pence resistor between centre pins
    check swap front SAM fuse F44 15A ( Inlet port shut off, Wastegate actuator, EGR valve and the Exhaust back pressure sensor)

    replace engine cover
    drive car
    don't give 2k to main dealer
    (STAR diagnostics for the win !!!)
     
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  4. Steve@Avantgarde

    Steve@Avantgarde Forum Supporter Authorised Forum Supporter

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    Ala
    Alan,

    Dont do any of the above, that isn't proper diagnosis, and the suggested fix? Well, I've seen that done and I've also had problems as a result.

    Looks like you have an IPS failure there or possibly a sticking manifold flap. If you had STAR you can actuate all components in about 5 mins and confirm the diagnosis.

    An IPS motor isn't £2k either.
     
  5. Botus

    Botus Senior Member

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    ….remove turbo, snap 2 of the bolts drill out and Heli-coil (3hrs), buy a set of studs, remove inlet manifold and discard (2hrs), use three gallons of engine degreaser in the V, remove the slightly weeping oil cooler and swap the O rings, (2 hrs), fit a new IPS and inlet manifold and refit your original turbo (4hrs)

    that looks like 11hrs at £80 an hour (lets pretend the other 2 hrs they normally charge are free today)
    parts 500, 90, and 80 for bits and bobs

    only £1600... plus the other bits they break and the other 2 hours they will charge....

    other method DIY at home for £1, when the car's value 1500,
     
    Last edited: Aug 10, 2018
  6. Steve@Avantgarde

    Steve@Avantgarde Forum Supporter Authorised Forum Supporter

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    But it doesnt need an oil cooler...and you don't need to remove the turbo to replace the IPS either....no actual diagnosis has been done yet so why the scare fest?

    If you remove the turbo bolts when they are hot, you won't snap them either. I've never snapped one yet and I must have removed about a thousand turbos from 642s over the years.

    Reading this kind of crap advice is why I've dodged the forums lately. When you question the posts which bleed bad advice or bodge job repairs its the professional that is the one questioned or attacked. And for putting the correct advice as well!! You would think I don't make a living fixing cars eh.
     
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  7. Westheath

    Westheath Senior Member

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    I think the intent is to be helpful but the posts end up nonsensical garbage,
    perhaps English isn't the first language but the advice is still poor truncated or not.

    IMHO

    The purpose of forums like this one is to ask questions and decide what answers you want to take action on.

    Its interesting to see the "knee jerk" bodges v thoughtful diagnosis and correct repair method.

    Cost may be the deciding factor for a lot of members here,
    so not all questions answered with the correct method of repair will be effected,
    and the bodge the preferred result.

    Steve@Avantgarde, possibly like myself, have seen bodges end up doing more damage to the customers vehicle and wallet.





    .
     
    Last edited: Aug 10, 2018
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  8. OP
    AMck

    AMck Senior Member

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    2007 E320cdi S211, SL320 2000(written off), 2007,Volvo C70 D5, 1976 Ford Gran Torino, 1978 VW camper
    Thanks for replies. Hi Steve, long time no speak - hope you're well.

    Ok, firstly an update. As per original post I went through diagnosis and testing of turbo actuator, exhaust back pressure sensor, inlet port shutoff motor and also EGR.

    Initially everything checked as OK using STAR. However after a few days the IPS checked as not ok. At this point I used the cheap fix of a 4.7k ohm resistor to bridge the connector. This removed the IPS fault, but it didn't change the fault in terms of low power and high exhaust back pressure code.

    I cleared the codes a few times and checked freeze frame data from when a new code was generated and on one of these occasions it showed the high exhaust back pressure code was generated with an engine speed of 0 rpm. So I decided to take a little bit of an educated guess and fitted a new exhaust back pressure sensor yesterday. This also being the cheapest and easiest thing to replace. The good news is it has been running fine since then with no loss of power hot or from cold - hopefully this will continue.

    This does still leave me with the IPS to sort and to determine if it's just the motor or the flaps sticking/brocken. It did look a bit oily over the motor, so a new turbo to inlet seal will also be fitted.

    Steve you mention you don't need to remove the turbo to replace the IPS. The procedure on STAR states the turbo has to be removed to replace the IPS motor - is there another method?

    Regards

    Alan
     
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  9. Wighty

    Wighty Senior Member

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    Sounds good so far buddy . Just a thought with the ips motor , are you able to check on Star the operation of the flaps in case it is them that have fouled and then caused the ips motor to fail . Because if it is the flaps getting gunged up in the manifolds then replacing the ips motor won't help and you may be better leaving the resistor in place to stop the pounds adding up ? As a fellow om642 owner these thoughts are in my mind as well . I know if my oil cooler seals go I might as well get the manifolds cleaned as well and maybe a recon turbo whilst I'm at it .
     
  10. onefortheroad

    onefortheroad Senior Member

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    this should be the 1st port of call with these symptoms on the om642 , seems to be common problem tbh .
     
  11. OP
    AMck

    AMck Senior Member

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    To do this you have to disconnect the motor from the flaps, which, from what I've read on STAR involves removing the turbo for access. Then if the motor fails the test a new motor is required, after checking flaps are free as if not the new motor will also fail.
     
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  12. Wighty

    Wighty Senior Member

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    Let's hope it's just the motor then , I suppose the drips from the turbo inlet seal may have destroyed it . Good luck with it
     
  13. Steve@Avantgarde

    Steve@Avantgarde Forum Supporter Authorised Forum Supporter

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    Hi Alan..

    Has been a while, hope you're well.

    You can get to the IPS without removal of the turbo, its a bit fiddly if you are a virgin at doing it and don't have the correct tools. If you remove the fuel filter, undo the IPS, separate the wiring trunking i find there is enough room to do the job.
     

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