DCT - anyone getting an occasional "granny" shift?

[Nautik]

FIXED - BMW Germany is replacing the entire transmission under warranty.

Under normal driving I've been getting an occasional "granny" shift. Normally it does it in D mode (I drive in D4 normally). It typically does it several times on my 20-25 minute daily commute.

Generally when it happens I am pressing down on the throttle, it is like the clutch slips, the engine revs up another 500-1000 rpm as my foot is still gently on the throttle, and then it will finally shift with a bit of a sloppy jolt.

It seems to happen more frequently between 4-5 shifts but has done it with other gear shifts too.

The only other thing that could be related is I got the TRANSMISSION MALFUNCTION error a few weeks back again under normal acceleration conditions. I lost all odd numbered gears. When I restarted the car in my garage it was fine. I took it to the dealer, they cleared the code and called it a day. Some forum members in the thread for that particular issue have mentioned in specific cases it was caused by too much clutch pressure in one of the clutches. I told the dealer to check for this but no idea if they actually did.

I also asked the dealer to update the DCT software but I don't even know if they actually did that. The TRANSMISSION MALFUNCTION has not come back yet but it is still suffering from this occasional "granny" shift.

Any ideas what to do? I was thinking of maybe getting one of the coding vendors to validate what updates are actually installed and if needed updating to the most current software...

I hate not being able to trust the dealership's work...

[Transfer]

Not normal. If you can replicate it and it's noticeably not right, I'd take it to a different dealer. Sounds like you have an issue with one of the clutches.

[ES_TRADER]

Never happened to me and I've had my software fail on me twice since the car was new

[BIGW0RM]

Ive had my dct clutch "slip" it into gear before. It's strange, one time I'll shift and it will chirp the tires. Another time I'll shift from the same gear at the same rpm (let's say 7k) and I'll feel it engage a little, but fully engage 500 rpms later. I assumed this was the dual clutch I was feeling.

But i don't know about it doing it in D mode as I don't do D mode.

[Nautik]

Thanks guys, looks like I need this looked into... ugh.

[gblansten]

Never driven in D mode before.

[Nautik]

It does it in regular mode as well. Trying to play with it a bit so I can reproduce it otherwise the dealership will just say they can't reproduce it and tell me to go away.

[WarrantyTracker]

Are you sure it's not just blipping the throttle on downshifts?

[Titanium Silver]

6MT FTW





jk

[Nautik]

Originally Posted by JBasham

Are you sure it's not just blipping the throttle on downshifts?

No, it only happens on upshifts. Every shift is perfectly smooth while driving minus the occasional terrible shift that causes a bit of a jolt because the clutch engaged too slowly and the engine jumped 500 rpm before it engaged.

I'm gonna get the bottom of this. Last thing I need is some DCT issue when the warranty runs out.

[iveman89]

Im not sure if this is the same example, but If I drive my car in D5( or D4 maybe?) with M mode I have a jolting/ bucking problem. Car kicks badly,(learning to drive stick kicking lol) moving off the line. I realized that being too slow on the gas pedal was the cause. lowering it down to D3 and I could be smooth and gentle. Not on the higher modes.

[Nautik]

Update: I am updated to the latest BMW software. The car still does it... Occasionally on an upshift in S mode (usually from 2-3 in this case) I will pull the shift paddle and it may take over a full second before the car decides to change gear. When it does, it is a sloppy shift.

It really does feel like shifting a manual if you were to let the clutch out slow before the engagement point, give a little much gas, and then dump the clutch.

I was convinced it was software but now with the latest BMW update and it still occurring I'm not so sure.

I guess I will just need to go back to the dealership and drive a tech around for 30-45 minutes until it does it.

[Nautik]

By the way, the new software update defaults D mode to D3 instead of D4 for me. Does not seem to make a difference in stopping the issue though.

I'll update this thread again when I get the time to go hang out at the dealership all day until I can reproduce the issue for them.

[jrlee53]

Sorry couldn't resist

[///WeissBisBlau]

D mode should default to whatever you had it on when you last stopped the car, or at least mine does, with comfort access. I haven't driven a whole heckuva lot in D4 or D5, but to date I have not noticed any "sloppy shifts" with mine, so I think you've definitely got a clutch issue. If I were you, I'd definitely shop around at different dealers. Check dealerrater.com, and look for one nearest you with a decently rated service department. Does it happen when your car is warm, or cold, or it doesn't matter?

[Nautik]

Originally Posted by JDy80

Sorry couldn't resist

Haha I know right? I think Granny shift is not really the technical term I should have used ;p

[Nautik]

Originally Posted by ///WeissBlitz76

D mode should default to whatever you had it on when you last stopped the car, or at least mine does, with comfort access. I haven't driven a whole heckuva lot in D4 or D5, but to date I have not noticed any "sloppy shifts" with mine, so I think you've definitely got a clutch issue. If I were you, I'd definitely shop around at different dealers. Check dealerrater.com, and look for one nearest you with a decently rated service department. Does it happen when your car is warm, or cold, or it doesn't matter?

Does it cold and when warmed up fully.

What I don't understand from a mechanical standpoint is it really seems to only happen under normal acceleration. I do not notice anything when in S5 and shifting under full throttle at high RPM.

It does not happen frequently enough to annoy me very much but something is certainly not right because no one else seems to have this issue. I'm used to the smooth as silk shifts it normally does when driving casually to work and then out of nowhere it will throw a bad one at me. Sometimes in S mode its like, I told it to shift right? Then right as I start thinking that, the sloppy shift happens.

I got about 1000 miles of warranty left but this issue has been documented several times at the dealer and my SA said they would continue to work on it even if out of warranty. I might have to get that in writing before I hit 50k!

[nullrouted]

Why not give Mike Benvo's DCT tune a try? Could be the easiest/best solution for you as long as the hardware isn't your problem

Review: http://www.m3post.com/forums/showthread.php?t=861000

[Edward]

Not to hijack, but I notice something happen pretty frequently.

When I am in S5 and go in first gear at moderate throttle to about 3200 rpm and let off the throttle while shifting up to 2, the car does a fairly aggressive little blip on the throttle. And then it takes a second to engage 2nd gear to keep it going. It's fine and I enjoy the sound but I don't see why the car is doing this unless for some reason it just expected me to keep on the throttle in 1st.

[///WeissBisBlau]

Originally Posted by Edward

Not to hijack, but I notice something happen pretty frequently.

When I am in S5 and go in first gear at moderate throttle to about 3200 rpm and let off the throttle while shifting up to 2, the car does a fairly aggressive little blip on the throttle. And then it takes a second to engage 2nd gear to keep it going. It's fine and I enjoy the sound but I don't see why the car is doing this unless for some reason it just expected me to keep on the throttle in 1st.

Yeah, so if you read one of the engineering docs you can find about the DCT, around here, you'll see that it is intended that you (the driver) do not have to lift off the throttle for it to shift, and it is in fact kind of designed for you not to. In S5 (and to a lesser degree S4), the program will aggressively rev match like that.

OP, I would definitely get that in writing--what your SA said!

[Edward]

Originally Posted by ///WeissBlitz76

Yeah, so if you read one of the engineering docs you can find about the DCT, around here, you'll see that it is intended that you (the driver) do not have to lift off the throttle for it to shift, and it is in fact kind of designed for you not to. In S5 (and to a lesser degree S4), the program will aggressively rev match like that.

OP, I would definitely get that in writing--what your SA said!

Yea, it's just that the few times I get going and have to let off immediately at that point, I notice it blip upwards as if I kept my foot on the gas but pressed in a manual clutch quickly to let it rev up freely. It's odd but I don't mind it. Of course when accelerating in general I don't lift off the gas.

[Nautik]

Originally Posted by nullrouted

Why not give Mike Benvo's DCT tune a try? Could be the easiest/best solution for you as long as the hardware isn't your problem

Review: http://www.m3post.com/forums/showthread.php?t=861000

Oh trust me, I'm one step ahead of you But we didn't want to take the chance it was a hardware issue and then the dealer try to blame aftermarket software. So I'm on stock software and I suspect they will need to look at the clutch now once I can demonstrate the issue.