[ajvdh]

Originally Posted by Artemis

From the BMW rear differential replacement 0033990100 'Technical Action' doc (July 19, 2016):

"Auswirkungen: Die Lamellen im Hinterachsgetriebe verschleißen sehr schnell. Es kommt zu massiven Geräuschen im Hinterachsgetriebe."
"Effects: the rear differential blades wear out very fast. Massive noises from the rear differential."

Hm, could that explain the weird metallic ramble that several (including me) reported about ? That occasional, peculiar grinding/screechy rambling noise coming from the rear underside.

If it happens to be the rear diff issue (which we don't know yet), then BMW has to recall (much) more cars than the batch starting from May 12 production onwards. Mine is an early April build.

See these earlier posts:

Just to add to the list: My car is a February build, and one in a while I hear a brief grinding noise from the rear. Kind of like "GRANK!"

[Twix]

Originally Posted by PackPride85

Most likely bad gears that slipped by QC.

Bad gears or meshing makes a different sound than what most are describing or hearing. Sounds more like clutch packs or pinion bearing

[MTHRAR]

I had the the tin can noise as well (February Build). This was the same day, just after I had some sort of shims replaced on my front wheel area (between rotor and hub - it was hitting the brake shields).

Now, what is funny is I heard "the new noise" coming from the rear and knew it was what the F80/82/83 crowd heard as rocks getting stuck in the brake shield.

The video directly below was my first issue with a noise, which sounds nothing like the other two videos and was corrected after those shims were replaced (apparently there is a service bulletin out on this issue as well):

This is what I heard from the rear or otherwise known as "Rock in brake shield" M3/M4 Videos below:

[Artemis]

Originally Posted by MTHRAR

I had the the tin can noise as well (February Build). This was the same day, just after I had some sort of shims replaced on my front wheel area (between rotor and hub - it was hitting the brake shields).
Now, what is funny is I heard "the new noise" coming from the rear and knew it was what the F80/82/83 crowd heard as rocks getting stuck in the brake shield.
The video directly below was my first issue with a noise, which sounds nothing like the other two videos and was corrected after those shims were replaced (apparently there is a service bulletin out on this issue as well):
[VIDEO]
This is what I heard from the rear or otherwise known as "Rock in brake shield" M3/M4 Videos below:
[VIDEO]

The noises in your three videos are likely caused by pebbles that entered the brake system, as you guessed.

The ramble noise we are referring to, is significantly different. It's a brief metallic grinding/rambling/cluttering noise. Happens at random and lasts less than a second or so. Always from underneath the car, rear end. Hard to describe how it sounds: as if you got a metallic lunchbox with a fork or knife inside, and you're briefly somehow shaking it sideways: some metal-against-metal rubbing/screeching.

If you hear it for the very first time, it startles you as you immediately think that something screwed up. But after a couple of times, you kinda 'get used to it' (similar sound) + no impact on driving. Just a nuisance, except if it turns out to be some car internals (rear differential ?) progressively getting damaged (which we don't know, as we speak).

[MTHRAR]

Originally Posted by Artemis

The noises in your three videos are likely caused by pebbles that entered the brake system, as you guessed.

The ramble noise we are referring to, is significantly different. It's a brief metallic grinding/rambling/cluttering noise. Happens at random and lasts less than a second or so. Always from underneath the car, rear end. Hard to describe how it sounds: as if you got a metallic lunchbox with a fork or knife inside, and you're briefly somehow shaking it sideways: some metal-against-metal rubbing/screeching.

If you hear it for the very first time, it startles you as you immediately think that something screwed up. But after a couple of times, you kinda 'get used to it' (similar sound) + no impact on driving. Just a nuisance, except if it turns out to be some car internals (rear differential ?) progressively getting damaged (which we don't know, as we speak).

Ok, I gotcha now! I don't think I've experienced this noise yet, but definitely heard the "pebble in the brake shield" issue. It was a continuous scrape, scrape, scrape noise that I could hear as I was speeding up or slowing down and the sound was spread evenly when I would be rolling down the street as if it was in the wheel. Thank you for the explanation Artemis !

[Artemis]

Originally Posted by MTHRAR

Ok, I gotcha now! I don't think I've experienced this noise yet, but definitely heard the "pebble in the brake shield" issue. It was a continuous scrape, scrape, scrape noise that I could hear as I was speeding up or slowing down and the sound was spread evenly when I would be rolling down the street as if it was in the wheel. Thank you for the explanation Artemis !

I experienced that 'locked pebble' sound once in the past 7500 km for an hour or so. Truly an annoying screechy scraping sound coming from one of the wheels: goes faster and slower depending on your speed. Finally managed to get rid of it after some serious twisting and turning and emergency brake stops. Luckily, because sometimes it's impossible to get rid of a locked pebble without dismantling.

[Prodigy.]

Originally Posted by Artemis

The noises in your three videos are likely caused by pebbles that entered the brake system, as you guessed.

The ramble noise we are referring to, is significantly different. It's a brief metallic grinding/rambling/cluttering noise. Happens at random and lasts less than a second or so. Always from underneath the car, rear end. Hard to describe how it sounds: as if you got a metallic lunchbox with a fork or knife inside, and you're briefly somehow shaking it sideways: some metal-against-metal rubbing/screeching.

If you hear it for the very first time, it startles you as you immediately think that something screwed up. But after a couple of times, you kinda 'get used to it' (similar sound) + no impact on driving. Just a nuisance, except if it turns out to be some car internals (rear differential ?) progressively getting damaged (which we don't know, as we speak).

This is exactly what I've been hearing, I've been passing it off as stones getting trapped but after hearing the videos that MTHRAR posted I've realised it sounds nothing like those.

[Artemis]

Originally Posted by Prodigy.

This is exactly what I've been hearing, I've been passing it off as stones getting trapped but after hearing the videos that MTHRAR posted I've realised it sounds nothing like those.

Checked a German M2 forum and some equally report about the grinding/rambling noise, described by some as "the noise of driving over a Cola can". So here we go: the can crunch noise...

"I already had several times a rambling noise, as if I drive over a Cola can or something alike. I personally noticed it, for example when I drive at low speed with open windows through the city. Pedestrians looked back, startled, as if I had driven over something, though I hadn't. I cannot yet pinpoint this, as I don't know where it comes from. I cannot provoke this noise. Happens with cold and warm [engine] circumstances. Has anyone an idea ?"
"Ich hatte schon mehrfach ein klapperndes Geräusch, als wenn ich über ne Cola-Dose oder so etwas fahre. Ich habe es selbst festgestellt, wenn ich z.B. bei langsamer Geschwindigkeit durch die Stadt mit offenem Fenster fahre. Fußgänger schauten sich schon erschrocken um, als wenn ich irgendwo drüber gefahren bin - was aber nicht geschehen ist. Kann ich leider nicht näher zuordnen, da ich nicht weiß woher das kommt. Ich kann das Geräusch auch nicht mutwillig erzeugen. Passiert in kaltem und warmen Zustand. Hat jemand ne Idee?"
source: here

"I also already experienced this one time; I immediately activated my hazards and checked under [the car], though have not seen anything; when I resumed driving I briefly heard it again and nothing ever since; really weird :/"
"Ich hatte das auch einmal, sofort Warnblinker an und runtergeschaut, es war aber nichts da, beim weiter fahren war es auch kurz wieder da und seitdem nichts mehr, echt komisch :/"
source: here

"Now that your saying this, I also remember such a slight rambling while driving, as if something was rattling. I immediately stopped, but did not find anything suspicious. I drove on and the noise was gone. Really strange."
"jetzt wo das sagst, erinnere ich mich auch an so ein leises Scheppern während der Fahrt, so als ob da irgendwo was klappert. Ich habe sofort angehalten, aber nichts Verdächtiges gefunden. Bin dann weitergefahren und das Geräusch war weg. Wirklich komisch."
source: here

"But it really sounds brutal, as if I drove behind a "Just Married" car with Cola cans. "
"Aber das hört sich echt brutal an, so als wäre ich hinter einem Hochzeitsauto der Coladosen hinten hat "
source: here

"That's exactly how it sounds !"
"genau so hört sich das an!"
source: here

[Fuman]

Originally Posted by ajvdh

Just to add to the list: My car is a February build, and one in a while I hear a brief grinding noise from the rear. Kind of like "GRANK!"

I've had the same loud metallic thud/grank at about 600km from delivery. It happen when the engine was at autostop, I had to accelerate hard, the auto start kicked in, and the loud noise thud/grank was produced. I've since coded out the damn autostop.

Following this I started hearing transmission chatter when idle. It is like a flywheel chatter. Goes away when clutch is engaged or at higher idle -- As in you can head the noise disappear. The chatter was not there on day one (I'm sure because I would not have accepted delivery if I heard this noise in the quiet delivery room). Also it's quieter or louder at times.

BMW AU changed the clutch but the chatter was still there. I did suggest to them at the onset that the flywheel needs to be looked at. It like a broken spring Center flywheel. But they insisted clutch. Eventually I was told that the loud transmission chatter noise is normal if mdct.

BMW AU also pointed me to the manual that says mechanical engagement noises are common -- I said this is a chatter not mechanical engagement noises. Honestly, I can tell the difference between an engagement noise which I think is a form of engineered art versus a chatter.

Overall it sounds like marbles in a tin -- not that loud but obviously noticeable in the cabin. Let's just say I wouldn't drive without music in the background. Pretty disappointing for a rather expensive German car in AU. BMW AU seems to think it's ok hence little effort in continuation. I've also run out of motivation to convince them - I do have other better things to do.

I'm just living with it. Waiting for more community feedback. Apart from this tin can transmission, I do love the M2.

[gmzanatta]

Originally Posted by Fuman

I've had the same loud metallic thud/grank at about 600km from delivery. It happen when the engine was at autostop, I had to accelerate, the auto start kicked in, and the loud noise thud/grank was produced.

Following this I started hearing transmission chatter when idle. It like a flywheel chatter. Goes away when clutch is engage or at higher idle. The chatter was not there on day one (I'm sure because I would not have accepted delivery if I heard this noise in the quiet delivery room). Also it's quieter or louder at times.

BMW AU changed the clutch but the chatter was still there. I did suggest to them at the onset that the flywheel needs to be looked at. Eventually I was told that the loud transmission noise is normal if mdct.

Overall it sounds like marbles in a tin -- not that loud but obviously noticeable in the cabin. Pretty disappoint for a rather expensive German car in AU. BMW AU seems to think it's ok hence little effort in continuation. I've also run out of motivation to convince them - I do have other better things to do.

I'm just living with it. Apart from this tin can transmission, I do love the M2.

I think with the on-going recall you are well within your rights to ask for your diff to be replaced. Since it is not a safety issue, you can keep driving the car until the part becomes available.

[Fuman]

Originally Posted by gmzanatta

I think with the on-going recall you are well within your rights to ask for your diff to be replaced. Since it is not a safety issue, you can keep driving the car until the part becomes available.

Is there a TSB for reference that someone could help point me to??

Much like the HPFP and wastegate issues on my previous n54 motor, there seems to be a difference between BMWNA and AU support.

I need something concrete to stand on and present to BMW AU.

[Chuck W.]

Originally Posted by Fuman

Is there a TSB for reference that someone could help point me to??

SI B33 04 16. Service Action: Replace Rear-Axle Differential.

[ILIKEBMW'S]

Originally Posted by Chuck W.

SI B33 04 16. Service Action: Replace Rear-Axle Differential.

I just got notified from my dealer that the parts will be in on Wednesday for the recall. Much sooner than I anticipated. For those of us who already took delivery, they are doing an auto-ship to the selling dealer.

[bubz0429]

Has anyone else been told by Genius that there is no more an estimated completion date on your work order being completed at VPC??

[gmzanatta]

Well folks, my car has been fixed, picking it up tomorrow.

If anyone is in the situation I was in (and lives in Canada), PM me.

[LGWGN]

Originally Posted by gmzanatta

Well folks, my car has been fixed, picking it up tomorrow.

If anyone is in the situation I was in (and lives in Canada), PM me.

I was hoping this was going to be the post I read when I saw this thread at the top!

A toast to this post!!!

[Ex-MINI]

Mission accomplished...

[Benzima]

Originally Posted by gmzanatta

Well folks, my car has been fixed, picking it up tomorrow.

If anyone is in the situation I was in (and lives in Canada), PM me.

PM the info. I will be prepared

[jtodd_fl]

Originally Posted by gmzanatta

Well folks, my car has been fixed, picking it up tomorrow.

If anyone is in the situation I was in (and lives in Canada), PM me.

Super excited for you. Can't wait to read your posts after driving/owning it for a while.

[luvmybmmr]

Originally Posted by jtodd_fl

Super excited for you. Can't wait to read your posts after driving/owning it for a while.

Agreed!!

[kylejdavidson]

Originally Posted by gmzanatta

Well folks, my car has been fixed, picking it up tomorrow.

If anyone is in the situation I was in (and lives in Canada), PM me.

Congrats! Incredibly jealous.

[SW19]

Originally Posted by gmzanatta

Well folks, my car has been fixed, picking it up tomorrow.

If anyone is in the situation I was in (and lives in Canada), PM me.

Finally,that is great news.

Enjoy!