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SMG Shifting Problem will not go away

Discussion in 'E46 M3 (2001-2006)' started by keca10, Mar 17, 2009.

    keca10 guest

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    I posted about this on a number of M3 forums trying to get an answer. No luck so far.

    Here is the deal:
    In the 6 months that I owned my car, I noticed the gears grinding about 20 or so times (always when shifting to 4th). It doesn't happen often but it sounds horrible and the gear doesn't engage for a few seconds. It sounds kind of like a bad manual driver not using the clutch well and ramming and grinding the gears. It happens in any driving mode (manual or auto) and on any setting number (happened in all settings 1-5). I can watch the revs jump up and down while the car is struggling and trying to engage the gear as well. The mechanical grinding noise makes me cringe just remembering it.

    It doesn't seem to be dependant on the temperature of the engine (it has happened in the first 1 minute of driving and after 2 hours). Outside temp also doesnt matter.

    I went to the dealer and they couldn't reproduce it. I can't reproduce it even right after it happens no matter what I try. It is just random! Happened today and it grinded twice during the same shift (tried once then tried again to get to 4th gear). I have a 2005 SMG M3 with Comp package and 22k on the odometer.

    Only once did the SMG orange light go on and it spit out error codes: FC B2 SMG. I have no idea what they meant, but the tech's troubleshooting guide told him to run diagnostics (test plan B2360-S2SIF) on the SMG (why didn't they run the diagnostics last two times I was there?!?!?!). Diagnostics found problems and told him to update the software, and they did. This is what I was asking them to do first time I was there and the service advisor promised me there is no new software for the SMG on an 05 M3, and he looked at me like I was crazy. Oh well, I am glad they installed the software now.

    Well, it still keeps happening. It happens less often now (maybe twice a month) that the software was updated, and it's less loud, but the problem didn't go away. I complained to the dealer at least 5 times and it is all on the record.

    Has anyone had this issue? This problem wouldn't be bad if i could replicate it. Last time, the dealer kept my car over the weekend and it didn't act up. I am frustirated, someone else has got to have had this problem. I feel like it's rare so I could just live with it, but when it happens it even freaks out passangers (who quickly make fun of German reliability).
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    mooseheadm5

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    Where are you located? Find a good independent shop with an Autologic or GT1 that actually gives a crap about you and your problem and tell them to go ahead and drive the car until it happens.

    keca10 guest

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    I am in the Twin Cities, MN. I switched dealers and the other place in town took it more seriously. They had the shop foreman drive the car home and over the weekend. Of course the problem didn't happen to him. I think the fact that it would probably take 2-3 weeks before it happens makes it kind of hard to trubleshoot. Do you think it's OK to just ignore the problem since it doesn't happen very often, or am I damaging my transmission more and more beyond any hope by letting it continue happening?

    I just wish the dealer would take my description of the problem as enough to go ahead and at least try to diagnose something. It can't be that I am the first person this is happening to. It seems like the only do things by some guide, and probably for legal reasons they aren't allowed to be creative in solving problems anymore. But I could be wrong.

    keca10 guest

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    Happened again

    Just happened again today. Sounds like the transmission is eating away gears and falling apart when it happens. I don't know what to do. Can I take this to BMW NA? Dear isn't helping. I noticed in the service record the previous 2 owners also complained about this (they only had it for a few months, the guy before me sold it in less then a month). I know this is still a good car, but this issue has to be resolved!

    Any tips?
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    mooseheadm5

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    I would try to ask the dealer politely to contact NA for you so it doesn't seem like you are going over their heads... yet.
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    tritunes

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    Something to check

    In speaking with a tech regarding failures he has seen with the SMG transmission. Regarding the symptoms you seem to be experiencing, he recalled that the hood latch switch was failing in car he worked on. When the switch isn't closed, the transmission won't shift (that's why you can't shift gears if the hood is open). You might see if there's any truth to this for your car. He said the transmission is pretty robust, it wasn't the syncro in this case, it was the hood switch that was intermittently sending open/closed signals to the transmission.
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    EuroWerkz1

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    Sounds like a clutching issue to me...

    Have your dealer try to diagnose the clutch operation. It sounds to me that the SMG shifiting is working correctly but the SMG clutching action is faulty. There is a prescribed way to measure SMG clutch performance in the diagnostic procedure.

    Good luck to you.

    377253 guest

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    There is a few things you can try at home.
    1. Reset the clutch (in the manual)
    2. Change the tranny oil to RedLine MTL
    Let us know.

    keca10 guest

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    Update

    Well, it's been a while since I wrote about this issue. When I came back, the dealer went above and beyond expectation in trying to resolve this issue (Motorwerks BMW).

    They kept the car for about 3 weeks trying to diagnose a problem. They couldn't replicate it but they did change the transmission fluid. Software was also updated by a different dealer which did make the problem less frequent.

    Well, after the transmission oil change the problem happened about two more times and hasn't happened again. I think the combination of the software update on the SMG and the oil change did the trick. I did buy the car used, so maybe the previous owner put in a wrong fluid...who knows.

    377253 guest

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    keca0001,

    Could you post the BMW part number for the oil? It should be on your receipt? So we all could use as a reference.

    Thanks,

    keca10 guest

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    Oil

    Sure, the oil p/n was:
    83 22 0 406 941

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