DCT problems

[Kyle_e90]

8k miles now no problem at all.

[RPM90]

Originally Posted by Diver

The problem some are experiencing with lag may be related to the transmission shifting into second gear at low speeds. Try driving in the manual mode to completely avoid this.

Does the DCT start off in 2nd gear like the steptronic did, when in standard "auto" mode?
I hated that feature and don't understand why it would even be there.

I'm still concerned that it's not doing it's 'automatic' functions properly, especially during spirited driving into and out of turns.
Standard torque converter trannys, like the BMW steptronic, were/are pretty responsive to gear selection during more aggressive driving.

Even though the step, like most TC automatics, has a slight lag feel from a standing start, I don't recall any step driver reporting so much lag that it felt dangerous to merge into traffic.
Having that much lag from a standing start is not acceptable.
And, not having the trans select the proper gear for spirited driving, while in auto mode, ruins the fun and intent of a "sport" mode.

I can see the default "D" mode being programmed for best fuel efficiency, and that's why most TC automatics and dual clutch automatics tend to shift up as quickly as possible in that mode.
But in "sport" mode the system should be pretty responsive and even intuitive in that it uses sensors and software to decide which gear the driver will need.
If the driver is in 4th gear and is heavy on the brakes, and the system senses the driver initiating a turn, the system should know that a lower gear will be needed and shift down to 2nd with no lag.
If in "auto" sport mode the tranny isn't doing that, then BMW may need to do some more programming on the DCT to get it to respond better and quicker.

Rapid fire gear changes are awesome, but clutch control requires nuance and is the one thing I can see being problematic with dual clutch trannys. MT drivers have slightly different techniques on how they control the clutch. It's not just an on/off type thing.
Hopefully BMW will get the programming correct as I really want a DCT in my next car.

BTW, does the DCT have a CDV?
Has anyone checked?

[JB135MDCT]

Originally Posted by RPM90

Does the DCT start off in 2nd gear like the steptronic did, when in standard "auto" mode?

BTW, does the DCT have a CDV?
Has anyone checked?

Starts in first with manual select option for 2nd.

If there is a CDV, it is internal. Any one have a shop manual for the DCT?

[228iconvert]

Over 8,000 miles now and Thank God no problems. Had the reprogamming done also. I hope this is not a problem in the future because I love the DCT!

[RPM90]

Originally Posted by JB135MDCT

Starts in first with manual select option for 2nd.

If there is a CDV, it is internal. Any one have a shop manual for the DCT?

What do you mean by "internal"?

Does the DCT not have a clutch reservoir like the MT does?
I would think it's a hydraulic clutch, hydro-electric/servo.
Or does it use some form of electronic mechanical servo setup that doesn't need hydraulics for activation?

My wonder is if it's using a CDV could that be part of the problem, and if it does have one, then maybe removing it would help speed up the engagement.

[BuddhaPilot]

No CDV via word from a BMW engineer through the tech who dealt with my car when it was in last week. As we don't control the engagement of the clutch through a pedal, there is no need for one. I told him there is no need for one period as many of us with traditional manual BMWs remove it to improve clutch feel. He was surprised and stated that was the one of the main purposes of the CDV! My reply was that BMW needs to pay attention to the masses an understand that it is crap.

[JB135MDCT]

Originally Posted by RPM90

What do you mean by "internal"?

Does the DCT not have a clutch reservoir like the MT does?
I would think it's a hydraulic clutch, hydro-electric/servo.
Or does it use some form of electronic mechanical servo setup that doesn't need hydraulics for activation?

My wonder is if it's using a CDV could that be part of the problem, and if it does have one, then maybe removing it would help speed up the engagement.

Hydro-e-servo is internal, unlike external clutch pedal and slave cylinder.

Who's got the time to open up thier DCT?

[BuddhaPilot]

Well, less than a month later my car ended up back on the flatbed. While the DCT is still giving some problems, it wasn't the primary reason it's at the dealership this time. I was driving to work and the brake pedal went to the floor. Luckily, I like following distance so I managed to get the car stopped with the e-brake and downshifting with a couple of feet to spare from the car in front of me. Tried pumping the brakes back up and they didn't regain pressure. I managed to get it into a parking lot using the e-brake and called BMW roadside. I shut the car down for a few minutes and voila, brake pressure returned the next time I started it. Either way, I wasn't about to drive it.

As for the DCT, it's still got some quirks that have gotten worse the more miles I've put on it since it was last at the dealer. It's gotten where I drive it almost exclusively in manual now and most of the time with DTC turned off. I rolled on the gas pulling out of my neighborhood this morning and waited...nothing. Little more gas and the car is barely inching out as that car that was far away has gotten alot closer. The revs finally jump up and WHAM, we're in gear and off to the races. That's happened several times over the past week along with a couple of occasions where it thought I wanted launch control. I'm not a two foot driver, so I don't believe I gave the car any indication that I wanted launch control. Not to mention I didn't have sport mode engaged or the DTC off which I believe have to be set to get launch control. Kind of startling to step on the gas and all of a sudden see the checkered flag and hear gear engagement reminiscent of an SMG equipped E46 M3 slamming home 2nd and 3rd.

I'm seriously considering asking BMW for a buy back on this car or pursuing lemon law coverage. I just know as soon as I say the word lemon law, then I'm out a loaner vehicle and who knows how long it'll be before the issue is resolved. The DCT problems are enough at this point, but brake failure is a serious safety issue. Especially considering how often I have 1 or all of my kids in the car. Anyone have any experience with BMW on a buyback or lemon law claim.

MD Designs- I've been following your trials and tribulations. How did you initiate the process of your car getting replaced? I wasn't clear on if that's what you pushed for or if BMW offered that. I'm afraid of ending up in that position and having to "accept" a car with options or a color combo I really don't care for. My car is fairly low on options to begin with as it was the only silver and black 135 with sport pack that I found within 500 miles of here. Don't care to end up having to pay for premium packs, etc. just to get a replacement.

[tanik310]

I really wanted to get the DCT transmission after falling in love with the DSG on my 2008 VW R32. Now I see it has some issues but I wonder how widespread they are.

How is the launch control feature?

[sjp3003]

Originally Posted by BuddhaPilot

Well, less than a month later my car ended up back on the flatbed. While the DCT is still giving some problems, it wasn't the primary reason it's at the dealership this time. I was driving to work and the brake pedal went to the floor. Luckily, I like following distance so I managed to get the car stopped with the e-brake and downshifting with a couple of feet to spare from the car in front of me.

??? I've experienced clutch pedals going limp and a manual shifter falling apart in my right hand, but a limp brake pedal is a first and potentially the most dangerous. Good thing you were able to manage the situation. I'm keen to know what the diagnosis will be. Good luck getting it fixed correctly.

[BuddhaPilot]

Originally Posted by tanik310

I really wanted to get the DCT transmission after falling in love with the DSG on my 2008 VW R32. Now I see it has some issues but I wonder how widespread they are.

How is the launch control feature?

The launch control works pretty well when it comes to a compromise between wheel spin and getting the car off the line quickly. The stock runflats don't have the best traction to begin with, so I'm sure the car would be quicker/have less spin with some stickier shoes.

It seems like I'm in the overwhelming minority when it comes to DCT having problems and that's a good thing. With how high tech they are, it's obvious that the tranny was well developed before it made it into a production car. Few bugs and it seems they got the software right for the most part. There's no way to get it perfect as it can't think of what the human behind the wheel wants or expects it to do 100% or the time. I'd say one of it's biggest faults is how it can be sort of indecisive while in auto mode from a stop and go. You can even hear it shifting between 1st and 2nd a couple of times as you roll back on the throttle. Unfortunately that means a couple of seconds where you've expected the car to takeoff and it's not going anywhere.

There's a good chance based on the other issues my car is experiencing that it may be "that car" from the production run. I'm still waiting to hear something on the brake loss from last week.

[ParkNuts]

Honestly, I'm fed up with my DCT car. I hit rush hour every day, and the throttle lag from a slow roll is eating away at me. Navigating parking lots is also a challenge when I'm constantly at a slow roll. I'm going to take my car in and tell the dealership not to give it back to me until they resolve the issue. If they can't, I'm thinking about pursuing lemon law (it has put me in dangerous scenarios) or simply trading it in and picking up a manual 1. This is so frustrating...

[Rikx1M]

7500 miles and no issues...touch wood as the Brits say....

Build date may 2010, picked up June 2010....I find myself driving in sport mode most days and have minimal lag...nothing yet that was dangerous.

Recommend you videotape one of your drives/commutes as videotape evidence seems to get their attention. I do that all the time from everything like washing machines acting up etc...

Best of luck.

[BuddhaPilot]

Tomorrow will be a week that my car has been with the dealer this time. TO say the least, I'm a little sick of how many days my 7,000 mile BMW has spent there since I took ownership. They called me yesterday to come down to the dealership and drive the car with a technician as they can't seem to reproduce the conditions I'm having. I took the tech out and drove the car in auto mode as he requested, then as I would normally drive it in manual/sport mode/DCT off. For once, it validated most of my complaints with one of their people in the car. There were several times where I gradually rolled on the throttle almost to the point of hitting the kickdown switch before the car very suddenly starts accelerating. The "unwanted" launch control still hasn't manifested again.

I talked with him about how the transmission operates in the various modes to try to show him that I'd done my homework and wasn't just someone expecting this thing to do something it wasn't designed to do. He said that they had several customers complain of lag and weird shifting in various DCT equipped cars, but that the last software update had cured almost all of them.

[RPM90]

Originally Posted by ParkNuts

Honestly, I'm fed up with my DCT car. I hit rush hour every day, and the throttle lag from a slow roll is eating away at me. Navigating parking lots is also a challenge when I'm constantly at a slow roll. I'm going to take my car in and tell the dealership not to give it back to me until they resolve the issue. If they can't, I'm thinking about pursuing lemon law (it has put me in dangerous scenarios) or simply trading it in and picking up a manual 1. This is so frustrating...

That would frustrate me as well.
One of the major reasons to have a trans that will shift automatically is to be more relaxed in heavy stop/go traffic.
With a MT your clutch leg can get a bit tired, and the whole thing can be tiresome, but at least you still have control of how much or how little forward motion you want.

It does seem to be more of a programming thing though. I don't see that the problem is due to a mechanical design flaw, but we'll see.
As more DCT's get miles on them, design, mechanical, or programming issues will come to light.

Dual clutch trans is still new for BMW. Audi/VW had some teething problems early on as well, and newer DSG's are much better now.

[drufe]

The lag with my DCT at very slow speeds is getting more and more annoying. I too have started to use manual shift mode more often to compensate, but I bought an automatic for a reason. I shouldn't have to use that mode just so I can have smooth, reliable starts.

I also don't agree with some of the comments from the engineers here about it not being able to read our minds and know what gear it should be in. I'm stepping on the accelerator while it's in 1st gear. My wife's $22k Mazda knows that and accelerates immediately. The computer knows that I'm applying gas and since the DCT normally does shifts in sub-second time (reason I bought it), it should be able to get in the right gear and start accelerating just as quickly. Yet, it takes 2-3 seconds before the car starts engaging and moving. By that time, the car I'm pulling out in front of which was a safe distance away is now right on top of me probably wondering why I've just pulled out in front of them and not going anywhere. Very frustrating and embarrassing sometimes.

Funny though, I still totally love the car and haven't enjoyed driving anything else as much as this thing. If they could fix this problem, I would be elated.

[BuddhaPilot]

The dealer gave me the car back today-trans problems and lag still present. Looks like BMW is now fielding a lot of complaints about non-M DCT equipped cars. So, there is another software revision in the works. The service manager said it may be 2-3 days or 2-3 weeks before they hear anything. Either way, it just needs to be fixed and without it being at the dealer another week. The mysterious launch control in automatic mode hasn't manifested itself again either.

They found nothing as far as the loss of brake pressure. Not surprised with some of the things the car has done so far without ever setting a fault code.

Interesting note- BMW no longer uses a traditional vacuum booster in it's braking systems. A cam-driven vacuum pump is used because it provides a more constant source of vacuum and improves pedal feel.

[BuddhaPilot]

Damn car put itself in Park again today...twice! My son and his girlfriend were in the car the first time. I managed to get a video of it on my iPhone the second time it happened. Trans wouldn't come out of Park either time until I shut the car down, waited about 30 seconds, and then restarted. The traffic behind me wasn't too happy, but oh well. What can you do if the car won't come out of park.

Both times, it started chiming and showing the "!" as the car was slowing. Didn't know what it was for until it got nearly to a stop and popped into Park. Pretty weird in the first incident as I was in manual mode and I felt the shift lever trying to move in my hand.

C'mon BMW, find a fix!

[JB135MDCT]

Looks like an intermittent switch problem, maybe. Like a door switch or the DCT shifting mechanism. Some switches will force a park when you are very slow or stationary.

[BuddhaPilot]

Finally heard something from my service advisor today. BMW wants to replace the shifter, shift computer, and parking lockout mechanism, then reprogram the car again. Problem is all those parts are in Germany and I have to have a working car a week from now for a month long work related trip. I don't have much hope in that happening in that time frame.

The service advisor stated that the engineering dept said they haven't seen a 1er yet do what my car does. That tells us both that other DCT cars are having this sort of problem. We'll see what it does for the lag problems because I really think it has no hope of doing anything to fix that.

Either way, it's their last chance with this vehicle. I ended up posting my frustration on the BMW USA Facebook page. They deleted the post the first two times I put it up, but let it stay after the third attempt. I actually got several responses and one of them was from BMW. They said to expect a call from Customer Service. We'll see...

[BuddhaPilot]

Almost two weeks since I've last been able to drive my car and going on a month since this last incident started. I received a call from BMW NA Customer Support who promised they would get right back to me and already had researched my case. Three days later...still haven't heard anything. I'm less than two days from leaving on a month long trip and still don't have a car They even knew about the timeline I was on over 2 weeks ago.

Field rep was supposed to be in SC to take a look at the car and approve the replacement of the myriad of parts engineering wants to replace, but had a medical emergency enroute. That's understandable, but damn it, try a different route if that is what it takes to get this moving. It's pretty embarrassing to have a vehicle that your friends have nicknamed "Christine."

I've tried to build some goodwill with BMW and my dealership by not going straight to NHSTA or lemon law'ing this car like I've got every right to do at this point. Just incredibly angry that I'm still making payments on a car I can't drive and will end up coming out of pocket for a rental for a month. They even knew about the timeline I was on over 2 weeks ago. I'm just hoping they'll decide to come through with a loaner tomorrow afternoon, but I'm not getting my hopes up.

[IZAGLO]

Contact BMW NA and file a claim. They owe you compensation for your monthly car payment as well as compensation for all this aggravation. DO NOT let them off the hook on this. Business is business and BMW will negotiate with you or seek a lawyer if you are not happy with the result and go Lemon on them...At that point BMW will negotiate...But only seek a lawyer if all else fails. Once a lawyer is brought into this BMW will not communicate with you so try to get this resolved to your satisfation first then get out the big guns...Lemon lawyers do not charge you to file a claim...they only collect if there is a settlement. Lastly, BMW needs to step up and give you a loaner for your trip if your car is still in limbo !!