[24M4]

Took delivery of my ‘24 M4C XDrive just over three weeks ago. Now I’m starting to notice the sound of something vibrating, seemingly coming from the engine bay or behind the ID8 / cup holder area at a stop. Can’t quite narrow it down. I’d describe it more as a “cat purr” than anything else.

It seems to be most notable when coming to a complete stop at a red light. Or whenever letting off and on the brakes at a stop.

The exact sequence of events is as follows:
1 - Coast to a complete stop
2 - I hear the brakes compress as if they are gripping the rotors even tighter after the full stop (no additional pedal pressure applied by me; Auto Hold is off)
3 - “Purr”/vibrating starts
4 - Let off the brakes (i.e.: to creep forward)
5 - “Purr”/vibrating stops
6 - Press brake pedal again
7 - Steps 2 and 3 repeat for as long as I’m on the brakes. Endless cycle. Very annoying.

It seems to be directly related to the RPM increase when taking my foot off the brakes.

Here’s what I have established it is not: Cup holder cover, ID8 display screen, air vents, center console, etc. I even put the car on a lift and inspected for possible loose exhaust components vibrating under the front seats and making contact at idle. Everything is in place and tight as can be.

Seems to be coming from the engine compartment possibly, or behind the middle dash area. Can’t really tell. It’s hard to troubleshoot because I have to be in gear and rolling on/off the brakes to replicate.

This issue is fairly new as of about a week ago, and definitely consistent.

Very annoying to not know the source.

Anyone experience anything like this before?

[big_ed]

I just picked up my car seven days ago and have also heard a similar noise from time to time.

[Forzanerazzurri]

You gotta grease the kickstand on that gaming monitor

[Needsdecaf]

Check the cowl area for a stray cat. Usually they are the source of purring.





I kid. Sorry, this sucks. I hate hard to chase rattles. Best of luck!

[MJBO]

I feel like I might have heard something similar in my car on occasion. I’ve found adjusting the steering wheel (putting it back to the original position afterwards) seems to make the sound go away.

[Mike02z]

I’m very unhappy with my new 24 G82 interior noises. Buzzes and rattles all over the dash. A buddy and me when for a ride and while I drove he searched and nothing helped. When I schedule my 1200 mile service I’m going to let them know. Likely they’ll says it’s my hardwired radar detector blendmount and my hardwired BlackVue. The problem started well before and I’ve taken both out to test.

My 22 X3MC was quiet as a church mouse so I’m a bit disappointed that a 100k car has this many interior noises.

[N1rve]

Originally Posted by Mike02z

I’m very unhappy with my new 24 G82 interior noises. Buzzes and rattles all over the dash. A buddy and me when for a ride and while I drove he searched and nothing helped. When I schedule my 1200 mile service I’m going to let them know. Likely they’ll says it’s my hardwired radar detector blendmount and my hardwired BlackVue. The problem started well before and I’ve taken both out to test.

My 22 X3MC was quiet as a church mouse so I’m a bit disappointed that a 100k car has this many interior noises.

Maybe you got a Friday or a Monday car lol.

[Mike02z]

Originally Posted by N1rve

Maybe you got a Friday or a Monday car lol.

LOL! Do they put the actual date anywhere? Mine just says 06/2023. I know the Corvette guys used to swear if your car was built on a Friday you were screwed 😂

[Berzerker]

Originally Posted by Mike02z

I’m very unhappy with my new 24 G82 interior noises. Buzzes and rattles all over the dash. A buddy and me when for a ride and while I drove he searched and nothing helped. When I schedule my 1200 mile service I’m going to let them know. Likely they’ll says it’s my hardwired radar detector blendmount and my hardwired BlackVue. The problem started well before and I’ve taken both out to test.

My 22 X3MC was quiet as a church mouse so I’m a bit disappointed that a 100k car has this many interior noises.

I had a rattle/buzz behind my ID8 screen in the 24 as well. I drove with the foreman and he heard it. They held the car for a couple hours to put some insulation behind the mounting points. That solved the issue for me.

[24M4]

Update:

Since my initial post I came across these videos on my hair-pulling quest to try to find the culprit. Although they’re on a new G87, they show precisely what I am experiencing (mine is not as bad as this…. But will it get there?!). The first video captures the issue very well within the first two minutes. The second goes a bit in depth as to the most likely culprit.

Issue:
https://youtu.be/PYWRDNNdSp0?si=l6RFgRLUNDoMSoty

Likely culprit:
https://youtu.be/0fMxQaTZZJk?si=Afj60jE8IdOSLBv4

I’m only at about 1800 miles on my 2024 G82 Competition Xdrive. I’m concerned now that my issue will progressively get worse to the point of this guy’s in the video. It appears BMW service has acknowledged several other reported cases from what the second video says.

Any other G82 owners experiencing this by chance? Anyone else beyond 4k - 5k miles on a 2024 without the issue? I’m wondering if this is batch-specific.

P.S.
Center-notched, weigted pads differ across M2, M3 and M4’s? I’d have thought they’d be the same. (Second video)

Edit: I have no mods aside from Dahler exhaust valve controller and resonator deletes.

[contact335i]

As I posted elsewhere, this fixed it for me. Another poster mentioned that I should take my car to the dealership and show them this hack and how it fixes the buzzing/rattling. I might do that when I get a chance…

[24M4]

Originally Posted by contact335i

As I posted elsewhere, this fixed it for me. Another poster mentioned that I should take my car to the dealership and show them this hack and how it fixes the buzzing/rattling. I might do that when I get a chance…

Thanks for responding. It’s definitely not my ID8 display. I wish it was that simple. I think I may have found the issue…

https://www.bimmerpost.com/forums/sh...php?p=30609254

[nu2M]

This is my 2nd BMW and I’m not very impressed with its build quality. My G80 makes several rattles and humming sounds. I have the music on most of the time which drowns out this nuisance. None of my cars that I’ve owned/currently own do this. I’ll think twice before buying a bimmer in the future. Good luck with the fix.

[24M4]

Problem SOLVED!

TL;DR: Stock exhaust without resonators was to blame.

When I initally posted this about six months ago I had just had both my resonators deleted. Stock catted down pipes and stock rear muffler assembly remained intact. Just two individual mid pipes (*with no H or X pipe between for crossflow) were all that was different. The sound was great and it really made my G82 come alive and sound mean with nice burbles and pops in M1/M2. The annoying “purr”/vibration sound started on that very ride home.

Just to recap, it was most prominent after opening the exhaust valves and then closing them for the remainder of the drive for any amount of time. 100% recreatable everytime by opening the valves and then closing them after a bit. The purring sound and vibrations were not subtle. It was loud and very noticeable from within the cabin to the point that passengers would ask what the noise was. Very annoying as I couldn’t narrow down the source. Trust me, I tried.

I didn’t want to beleive it was the resonator deletes because it couldn’t be, right? I mean they were simply cut out and 3 inch pipes were welded in their place. Sidenote: No clamps, couplers, hangers, bushings, heatshields, etc., were loose whatsoever. Also, no clearance issue at all - anywhere. I was baffled. I checked (about six different times on a lift - car running and/or off). No amount of troubleshooting narrowed it down. So I gave up and just accepted it reluctantly.

A few weeks ago I had catless downpipes installed. For a little while I suspected that, while not likely, maybe some of the cat honeycomb internals had be shaken lose by the sawsall during the resonator deletes, and that was what was vibrating. Nothing else seemed to be the issue so while far fetched, maybe this was it. I hoped the catless downpipes would fix it if it was the case. It did not. The car sounded A LOT louder with no cats. But still had the issue. I also wasn’t too thrilled with the exhaust note.

Today I found the culprit. Totally unrelated to this purring/vibration issue I decided to - in addition to the catless downpipes, get a mid pipe and axle back exhaust system. The issue is COMPLETELY gone. My Dahler exhaust valve controller still works perfectly fine and now it doesn’t matter whether I run the exhaust valves full open all the time, closed all the time or anything in between. The god forsaken “purr” and vibration that has been the bane of my existence for the better part of six months is absolutely gone.

I guess the stock exhaust system does NOT like to be messed with in any way whatsoever. Maybe an x-pipe or h-pipe would have solved it previously by equalizing some harmonic resonance and resulting vibration. Who knows.

The car sounds 100% better straight piped and I now have a nice throaty roar note vice the raspy, tinny sound I had with the stock system and resonator deletes. And most importantly, I now have peace of mind without the damn purr!!

Shoutout to Steve @Euroklasse for getting me right! Thanks to everyone who chimed in with tips and recommendations. I appreciate it.

[Berzerker]

Love that the issue ended up being "make the car louder" lol

What system did you end up going with?

[24M4]

Originally Posted by Berzerker

Love that the issue ended up being "make the car louder" lol

What system did you end up going with?

Hell yeah! It sounded slightly better than an electric weed wacker stock. I needed some sound!

I went with MAD catless downpipes (MAD-2032), their mid pipe (MAD-5048) and axle back exhaust (MAD-5069). I love the sound. It has almost a V8-like idle. Having a Hellcat Redeye before the G82, I’m really liking the throaty, deeper rumble of this setup. I should have done it sooner.