Failed DMF?

[No_curebimmer]

I posted this in the M2C forum but I didn't get any feedback, so I am hoping my issues get more traction here since we share same motor and there are a lot more F80/82 on the road than F87.

I self-diagnosed the below issues to a failed dual mass flywheel (DMF). Am I on the right track?

Observed Symptoms:

1. Oftentimes, the first gear is extremely jerky. It does not happen every time, but enough to make me question if I can still drive manual transmission (which I have been doing for close to 30 yrs. now…)
2. Recently, I have started noticing that, while idling at stoplights, the engine is making this weird ticking noise, with a very a steady cadence (tacatacatataca). This noise simply goes away when I clutch in. Please see the quick clip below: the distinct ticking noise goes away around 3sec mark when I clutched in.
3. Not always, but clutching + shifting gears result in a noticeable 'clunck noise' that I can feel and hear.

https://drive.google.com/file/d/120K...ew?usp=sharing

Car details:
1. 2019 M2C (S55)
2. About 5,000 miles
3. 6 speed

It seems to me that the issues are related. So what do you guys think, is this pointing to transmission/DMF failure (excessive play between the 2 DMF halves), engine valve lifters (seems unlikely) or something else completely different?

The car is quite new given the mileage, so I'm surprised that something this major has failed.

Thanks in advance for any input!

Skål

[jpy1980]

I believe number 1 and 3 are normal, with 1 being more pronounced in Sport+. I have a manual F80. In regards to number 2, I’m not too sure but if it something more engine related? Sounds like the engine is knocking? Since your car should be under warranty, just take it to the dealer!

[chmura]

All those things unfortunately are pretty normal on an M car. You will hear clunking in a manual. I dont hear anymore stuff because I have my exhaust flaps always open. But what you describe doesnt seem like problems with the car IMO.

[No_curebimmer]

Yeah, thanks for the input guys, I appreciate it. Maybe I'm paranoid, but I didn't hear these kind of noises in my E46 nor E92, and the 330ci was deformity refined; I can't believe BMW is making louder machines nowadays. Still, It's reassuring that you guys think it's normal, but not all seems kosher to me, as they say.

Still, I will take it next week to the dealer for sure, but digging further into this, the ticking noise I hear while stopped, in neutral, clutch pedal not pushed in: it might be related to gearbox bearing. Breaking it down systematically, here is what I figured it might be:

1. if one engages the clutch, of course that means pedal is not pushed in and clutch disk is engaged to the flywheel. If noise is present in this state (like in my case) --> then this might point to a gearbox bearing failure.

2. otherwise, if clutch disengaged, that means the pedal is pushed in and clutch disk is disengaged from the flywheel. If there is a noise at this point, then likely the throw-out bearing might be the problem.


If that's true, it might explain the shitty 1st gear starts, I can barely control the car from stalling since the clutch isn't fully engaging/disengaging from the flywheel.

For posterity, will update this post once I hear from the dealer.

[No_curebimmer]

Originally Posted by jpy1980

I believe number 1 and 3 are normal, with 1 being more pronounced in Sport+. I have a manual F80. In regards to number 2, I’m not too sure but if it something more engine related? Sounds like the engine is knocking? Since your car should be under warranty, just take it to the dealer!

Yeah, engine knocking was my first thought and was going to pick up some Liqui Molly hydraulic valve lifter additive. However, I can make the ticking noise go away every time by pushing on the clutch, so kind of dismissed it.

I will next try to check if the clutch pedal is vibrating: slightly push in with the hand and see if it vibrates, then it will further validate gearbox bearing might be failing. I doubt it's the DMF though, not much can go wrong with it, especially after 4k miles

[jpy1980]

Originally Posted by No_curebimmer

Yeah, engine knocking was my first thought and was going to pick up some Liqui Molly hydraulic valve lifter additive. However, I can make the ticking noise go away every time by pushing on the clutch, so kind of dismissed it.

I will next try to check if the clutch pedal is vibrating: slightly push in with the hand and see if it vibrates, then it will further validate gearbox bearing might be failing. I doubt it's the DMF though, not much can go wrong with it, especially after 4k miles

I had some lifter tick so I used risoline engine treatment as per this video and it went away. https://youtu.be/3kBArthmDd8

[YRAGAEL]

I have these issues as well - 2016 F80 64k miles. First gear is often very 'notchy' and sometimes, if I'm sitting at a stop and the light turns green, I'll clutch in and cannot get the lever into first gear - it goes halfway and stops - until I clutch out, then clutch back in again.

I also have the driveline clunk sound and feel when I'm lucky enough to get the trans into first gear. Had this same issue on my previous E90 335i, so it's not unusual, just annoying.

I've noticed gear rattle when idling at a stop in neutral. I used to have an E36 M3 with a lightweight flywheel, so I know the sound. It goes away immediately on clutch in, but I thought it a bit unusual to have this happen with the OEM DMF.

Going to have the trans fluid changed and see if that helps anything.

As far as jerky-ness off the line, I also have this issue. I've been driving BMW manual transmissions for decades, and this is by far the most difficult to launch smoothly that I've ever had. A couple of remedies that have worked for me are:

1) Install the larger clutch stop from BMS - the stock clutch pedal travel is much too long before the clutch engages. The larger stop shortens that travel, making engaging the clutch much easier. YMMV, but it worked great for me.

2) Code out the rev-matching feature in all drive modes via the Bimmercode app. Yes it was nice to have rev-matching on down-shifts, since I'm too tall to heel-and-toe, but on up-shifts it just jacks everything up. We bought a manual trans car for a reason, so make it fully manual!

One more thing I'm going to try is to get rid of the stupid clutch delay valve that is hiding inside the clutch slave cylinder. The E90 335 slave cylinder is identical to ours, but does not have the restriction point that ours does. I have not done this mod yet, but I will soon. Already have the part.

[corbs09]

These are all normal, the dual mass flywheel/throw out bearing are known to make some noise (370z and the like do the same thing). As for the clunking etc, the subframes and diffs are mounted more solidly on these cars than the e46/ 330ci I believe, it will attribute to some interesting clunks if you abruptly clutch out.