Car jumps/bangs after coming off a stop!

[madrit21]

So after the car being warmed up and driven for about 2 miles, ill come to a complete stop and when i accelerate the car kinda jumps/bangs into gear. There are no codes being thrown. The car is DCT and ive had all the software updates and readaptations done. Also a fluid flush done as well. Car is at 30k. Any ideas??
Video:

[sibhusz06]

dumb questions, but you do have the right fluid in there and filled it to the proper level per the procedure?

[madrit21]

Originally Posted by sibhusz06

dumb questions, but you do have the right fluid in there and filled it to the proper level per the procedure?

I had the fluid flush performed at Autocouture Motoring (very reputable shop in NJ) so im guessing the right fluid was put in at a proper level. At least im hoping so since i paid almost 700 bucks for it 😂

[amrazM]

You may need a mechatronics, was it doing that before the dct service at acm?

[madrit21]

Originally Posted by amrazM

You may need a mechatronics, was it doing that before the dct service at acm?

Yes. They tested the mechatronics and it checked out good. No SES light either

[amrazM]

Originally Posted by madrit21

Yes. They tested the mechatronics and it checked out good. No SES light either

And it’s still doing this now? Hard to say this is fine, you should check the internal pressure with Ista

[madrit21]

Originally Posted by amrazM

And it's still doing this now? Hard to say this is fine, you should check the internal pressure with Ista

Still having the issue. Is the internal pressure something i can check myself? Or should i be done at a shop?

[madrit21]

Originally Posted by M3Post

Check the DCT mounts, as well as the engine mounts. To me the mounts look to be mechanically loose in your video and that results in the thud and jerk when you tap the gas. The engine mounts in DCT cars as well as the transmission mounts take a beating. In the video drive logic 5 shift program is displayed. Is the jerk/bump less in S1?

Is there any way i can check the dct mounts without a lift? (Dumb question)

[madrit21]

Is there any way i can check the dct mounts without a lift? (Dumb question)[/QUOTE]

Originally Posted by M3Post

Check the DCT mounts, as well as the engine mounts. To me the mounts look to be mechanically loose in your video and that results in the thud and jerk when you tap the gas. The engine mounts in DCT cars as well as the transmission mounts take a beating. In the video drive logic 5 shift program is displayed. Is the jerk/bump less in S1?

The jerk is the same in all settings. Seems to be more noticable when the car is warmed up and driven. If i ease the throttle it is not as noticable.

[madrit21]

Originally Posted by M3Post

It's possible but not advisable. You really need the car on a four poster lift. Then have a mechanic observe what's moving while another puts the car in gear and taps the gas.

Any decent independent shop should be able to do such a diagnostic for you. Since the behavior manifests the same in all shift programs we are back to mechanical hardware rather than software IMO.

Sorry you're having the problem and frustration. Get it up on a lift. Shoot some video then report back.

Much appreciated. Will get back with an update.

[Theodore]

+1 on what M3Post said. It is highly likely failing motor mounts are the main contributing cause (or the entire cause) of your car's hard shifting. It's one of the most common maintenance issues for these vehicles. 30k miles plus 10 years of use is more than enough for them to fail on an E9X M3, there are lots of reports of them failing early as compared to other models. The DCT mounts are an exceptionally rare failure point for these cars as they use solid rubber vs the fluid filled rubber of the motor mounts. You can read more about failing motor mounts in this thread here).

Another possible contributing factor could be a broken a diff bolt, which sometimes happens on these cars. Check out this thread for more details.

[madrit21]

Originally Posted by M3Post

Any news yet?

Had all the mounts and bolts checked. I was told it is a result of a worn clutch and must be replaced. 😫😫

[BrewRifle]

Worn clutch with 30k miles...seems suspect to me.

[madrit21]

Originally Posted by BrewRifle

Worn clutch with 30k miles...seems suspect to me.

It blows my mind that it can have this issue at 30k. There goes 4k out of my pocket. I have the parts coming. Nothing was installed yet.

[madrit21]

Originally Posted by M3Post

Wow. OEM DCT clutch is designed to last for 100sK miles. Strange that it could cause jerk and jump rather than just slip. Search the forums. I don't recall hearing any similar issues such as what yours is doing. Consider contacting BMW Regional area service manager for a second opinion. Good luck.

Thanks for the feedback. Random question for anyone that has an idea, but wouldnt a worn clutch throw a code??

[nycplumber]

Originally Posted by madrit21

Had all the mounts and bolts checked. I was told it is a result of a worn clutch and must be replaced. 😫😫

Who arrived to this diagnosis and how?

[Rainer M]

Originally Posted by madrit21

Thanks for the feedback. Random question for anyone that has an idea, but wouldnt a worn clutch throw a code??

A slipping clutch should show a code.
When I had problems with my dct, I was told by the service advisor that the input speed and output speed is monitored and if it didn't match (considering gear ratio) a code would come up.

My issue was ( and is) that from second to third gear change the car feels like it is slipping the clutch and then dumping it. Kind of a deceleration/ acceleration sensation. A little jerking. Most noticeable between second and third gear.

The DCT was supposedly replaced with new gear but that didn't do much.


There is a lot of communication going on between DCT and motor control.

I would start by get the clutch-in points "teached in" adaption reset of DCT and motor. torque settings and so on. In ista there is a whole punch of resets for the DCT.

[madrit21]

Originally Posted by Rainer M

A slipping clutch should show a code.
When I had problems with my dct, I was told by the service advisor that the input speed and output speed is monitored and if it didn't match (considering gear ratio) a code would come up.

My issue was ( and is) that from second to third gear change the car feels like it is slipping the clutch and then dumping it. Kind of a deceleration/ acceleration sensation. A little jerking. Most noticeable between second and third gear.

The DCT was supposedly replaced with new gear but that didn't do much.


There is a lot of communication going on between DCT and motor control.

I would start by get the clutch-in points "teached in" adaption reset of DCT and motor. torque settings and so on. In ista there is a whole punch of resets for the DCT.

Had all the recent updates done and the clutch readapted. Still having the same issue. What a nightmare.

[amrazM]

I am Still unsure that your clutches are the culprit here, be careful before you replace the clutch packs and then end up needing a gearbox.

[madrit21]

Originally Posted by M3Post

Any news?

Dropping the car off tomorrow for a clutch replacement. Should be getting it back by tuesday. Hopefully all goes well. Wish me luck 🤞🏼

[madrit21]

Originally Posted by M3Post

Good luck and let us know if the new clutch fixes the issue. Have em check the engine and DCT mounts while they are under it and have the transmission out.

Thanks alot man. Appreciate the feedback 👍🏼

[madrit21]

Originally Posted by M3Post

Any news?

Changed out the solenoids in the mechatronics. New mounts. Still same issue.