03-13-2018, 10:28 AM | #1 |
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Slipping DCT clutch
My 16 F82 has bolt ons and the VF Engineering Hex Stage 2 and TCU tune.
Now that snow season is finally gone I've contemplated spicing things up and going with an E85 BM3 tune, but the last time I took out my car and really got on the gas I believe the clutch slipped. I was in third gear, floored it from 3k rpm and around 5k rpm all of the sudden the revs increased quickly as if the car was in neutral, but the car didn't accelerate at all. I let off the gas and slightly depressed the gas pedal again and everything seemed normal. I have had this issue happen numerous times over the last 2 years but have never been able to reproduce it, and it seemingly happens totally randomly. Some days I've done a dozen hard pulls with no problems, but once it just happened on the first WOT pull. Is my clutch bad? Is the car making too much power already and going with an E85 BM3 tune is pointless unless I get a new clutch? Is there something wrong with my software adaptations since this issue happens to infrequently that a reset or reflash may cure the problem? Thanks for any input. |
03-13-2018, 04:09 PM | #2 |
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On stock turbos, your car isnt make enough turbos to split the DCT clutch.. but if the clutch has been abused enough, its possible.
Go back to the stock TCU tune, see if you can make it happen again.
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03-14-2018, 03:15 PM | #3 |
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I can't imagine what would have caused clutch abuse. I'm the first owner and only driver of the car. It has never been tracked or launched and I have never used the kickdown functionality. Before stepping on it I always make sure the car has warmed up etc, and it only has 6600 miles on it.
It also confuses me as to why it happens seemingly randomly. One day on my drive to work cruising along at 70mph for 30 minutes I go WOT before exiting the highway and it happens. Other days I can go WOT plenty of times and it doesn't occur. I'm at a loss as to what is happening. |
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03-19-2018, 09:58 AM | #5 |
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I'm in manual mode but I'm not using kickdown. This has happened simply by going WOT in third, fourth, fifth. I have never been able to intentionally reproduce it, and it happens very inconsistently.
Still, if the clutch is slipping at current power levels and resetting adaptations won't fix it there's not much point in trying to get more power before getting an upgraded clutch. |
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11-28-2019, 04:39 PM | #6 |
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Is there any update on this? I've had this happen to my stock CS a few times but it's so inconsistent I can't demonstrate it to my dealer.
Automatic, full kick down -> car revs but does not engage a gear until I let off the throttle and press it again. |
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02-24-2020, 05:21 AM | #8 |
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I’ve experienced this issue twice now.
First time: September 2019 Stage 2 Alpine MSS tune car fully warm, normally shifted into 4th and was getting onto the highway and was just sitting at constant speed revs at about 4/5K RPM, I accelerated at 60% for 2 seconds max and pulled the upshift paddle and the RPM pointer shot forwards to about 6.5/7K RPM and I could hear the engine rev up as if I had downshifted. Best way to explain is I upshifted and it sounded like a manual money shift. Traction was fully on and there was no way I break traction because I was already at 80KPH and tarmac was hot. Second Time: February 2020 Fully stock tune and stock DCT coding (NON-ZCP) I was going slower even and in 3rd gear, repeated the same thing and I didn’t even roll into full boost it was still spooling, I upshifted into 4th and same thing happened revs shot up instantly and heard the engine rev, luckily I wasn’t going as fast as the first time otherwise it could have over revved. Everything was normal straight after it happened. Asked my tuner and he said it just didn’t clear into the next gear, happens to DCT cars a lot...? Spoke to a local tuning company here and they said sounds like clutches. |
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03-27-2020, 11:22 PM | #9 |
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I am having the same issue as Kenny and Daxos. My car is fully stock with dct. Happened to me today when I was using around 75% throttle at 4k rpm and it scared the crap out of me. I thought I spun the crank hub. I'm scared to push the car even further because of the possibility that it can over-rev.
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03-28-2020, 07:10 PM | #11 |
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Just drove the car tonight. Same thing happened, on upshift car revd to 7k. I shifted at 5500. Imagine if I shifted at 7k and the same thing happened, spun crank hub? Taking it into bmw not going to drive my car hard until I figure this out. Car is completely stock and has never been modded.
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07-26-2020, 02:25 AM | #12 |
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My car has done the same thing a few times as well. If I get on it maybe 75-95% throttle and shift around 5,000-6,000 and then let off the gas, the RPM’s will instantly shoot up and the engine will rev on its own. 2015 M4 running BM3 stage 1 and THOR GTS dct tune. What could this be? It only has happened randomly but otherwise the car drives fine and strong.
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07-27-2020, 02:58 PM | #14 | |
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If it still slips with this software, then I would most likely rule out its clutch slippage.
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07-27-2020, 04:57 PM | #15 |
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I know it's a pain to check, but maybe there's a leak and the DCT is low on fluid/oil? We know it's a sealed system, but as my German buddies say..."Scheiße passiert" (shit happens).
Personally I would go get a liter of factory DCTF and break out my fluid pump to try and see if I could get any to go into the case. If the trans was full only one or a couple pumps would go in, and if it took more than a half liter I would start looking around for leaks. I know your car is low miles so it's unlikely, but if you're not taking it to the dealer for diagnostics I'd start here.
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07-29-2020, 06:04 AM | #16 |
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For the people worried about overrevving. That cant happen with dct. It will just cut off fuel and bounce at redline... you cant overrev with a dct tranny, but its possible on a manual tranny by downshifting when you are already at redline. Its a mechanical overrev and called a moneyshift.
I agree with trying the GTS dct flash to help with this problem. |
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04-10-2022, 09:40 AM | #17 |
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Anyone have an update to this? Same happened to me. Bm3 stage 1, GTS DCT flash. Was driving in 4th gear, gave it about 80% throttle and shifted up to 5th and then immediately let off the gas and the revs jumped up like I was reving it in neutral. Gave it a second and hit the gas again and it took 5th and had no issue from there. Wondering if anyone got an answer on why this happens?
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04-12-2022, 04:13 PM | #18 | |
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Also, The only time i experienced this I hit a pot hole the size of Russia then I hit the gas and car revved to 7k and car didn't move. I power cycled and haven't experienced it since
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