[T_R]

I am dealing with an incredibly annoying rattle from the back of my car. I live in an area with a lot of bumps (Jersey City, NJ) so I hear it a lot. It is more apparent when I hit bumps on the right hand side — but not every bump, and not on smooth road.

I've taken it to my dealership twice for the issue — once they could not replicate it, and the second time they had my car for two weeks. They drove it without the rear deck in and only identified some other issue from the front seat, which I had not heard before. The part I need for that is on backorder.

However, I am confident this is coming from the back and SOMETHING is loose. In the video below I am driving on a cobblestone road, which is the most efficient way to replicate the noise, it is constant on that surface.

YT video: https://www.youtube.com/shorts/tq5LN3XNASY

Has anyone else encountered this? Nothing seems loose from what I can tell, including the deck itself and the rear window shade. I am hoping to take this back to my dealer with this video and some actual instructions.

[G35c6MT]

Try folding the rear seats down and test again. I have a rattle that is due to some repairs but nothing as bad as what you’re hearing. Mine was in the clips that secure the rear side bolsters (backseat section between the seat and each door).

[T_R]

Originally Posted by G35c6MT

Try folding the rear seats down and test again. I have a rattle that is due to some repairs but nothing as bad as what you’re hearing. Mine was in the clips that secure the rear side bolsters (backseat section between the seat and each door).

I tried it with the seats down as well, and again with some microfiber towels stuffed against the rear window shade — no dice, unfortunately.

[mwilson122]

Are you sure it's not that iPhone sliding around on the rear shelf that's rattling? Starting at around 0:40 into the video.

[T_R]

Ha no it's not, good call though. That's my work phone, I wanted to see if recording it from that close amplified the sound a little. Turns out it was just as loud on both. It rattles with and without it there.

[dubb13]

Sure it's not in the suspension

[T_R]

They checked the suspension last time I brought it in — all checked out.

[dubb13]

What about the spare tire the jack I mean could it the muffler? Just throwing my two cents in because that s*** would completely annoy me man

[T_R]

Originally Posted by dubb13

What about the spare tire the jack I mean could it the muffler? Just throwing my two cents in because that s*** would completely annoy me man

Yeah it's super annoying. I checked everything in the trunk (and emptied it), also no go. I suspect I'll be bringing it back soon.

[AiredaleDad]

Do you have wheel locks? I have a wheel lock key in the compartment in the trunk lid where it goes along with the warning triangle, and the key in there comes loose. I have it secured with a small cloth to keep it from rattling.

[T_R]

Originally Posted by AiredaleDad

Do you have wheel locks? I have a wheel lock key in the compartment in the trunk lid where it goes along with the warning triangle, and the key in there comes loose. I have it secured with a small cloth to keep it from rattling.

I don't have wheel locks, unfortunately.

I am more and more convinced some little plastic part is loose or missing in or around the rear deck and it's just really hard to narrow down, especially since it's most easily replicated on cobblestones and these are about 30 miles away from my dealer.

[mwilson122]

Not sure if this is viable, but I wonder if you could try inducing vibrations in various places and see if it helps you narrow down the location. Like with a cheap massage gun you can find on amazon?

Edit: I meant inducing vibration from inside the cabin and trunk area, not a full substitute for driving over dragon's teeth lol.

https://www.amazon.com/s?k=massage+g...hl-bn-left_1_8

[dubb13]

Have had someone ride in the backseat?

[T_R]

Originally Posted by mwilson122

Not sure if this is viable, but I wonder if you could try inducing vibrations in various places and see if it helps you narrow down the location. Like with a cheap massage gun you can find on amazon?

Edit: I meant inducing vibration from inside the cabin and trunk area, not a full substitute for driving over dragon's teeth lol.

https://www.amazon.com/s?k=massage+g...hl-bn-left_1_8

That is a great idea actually, thanks! I have a Theragun at home, I'll see if I can replicate cobblestone without actually driving anywhere.

[T_R]

Originally Posted by dubb13

Have had someone ride in the backseat?

Yes I've had 3 people back there before and it still happens - and I have the added joy of getting the question "what's that noise?"

[dubb13]

That is some bullshit they would have to fix that how is it the dealer didn't hear that I meant it's pretty consistent did you consider taking it to a different dealer or call corporate and see if they can get you to dealer and open up a complaint because that's unacceptable

[miner4269]

Suspension related IMHO

[tsbrown]

In one of my past BMWs from nearly new I had a rattle in the back seat or rear shelf. After lots of searching it turned out to be the rear center headrest latch wasn’t tight or the headrest wasn’t in one of the detents. Try taking out the headrests and see if that isolates the noise.

[mwilson122]

Originally Posted by tsbrown

In one of my past BMWs from nearly new I had a rattle in the back seat or rear shelf. After lots of searching it turned out to be the rear center headrest latch wasn’t tight or the headrest wasn’t in one of the detents. Try taking out the headrests and see if that isolates the noise.

Wow this brings back memories of the last S-class that I owned; the right rear headrest rattled occasionally and drove me absolutely bonkers! Never got it fixed either, I kept forgetting to mention it during service visits.

[tsbrown]

Originally Posted by mwilson122

Wow this brings back memories of the last S-class that I owned; the right rear headrest rattled occasionally and drove me absolutely bonkers! Never got it fixed either, I kept forgetting to mention it during service visits.

So is your rattle a higher, middle or lower frequency? I would consider a higher frequency like the headrest rattle. Middle frequency is something in door pocket. And lower frequency is like a suspension rattle thunk/thump. This may help isolate where to look.

[mwilson122]

Originally Posted by tsbrown

So is your rattle a higher, middle or lower frequency? I would consider a higher frequency like the headrest rattle. Middle frequency is something in door pocket. And lower frequency is like a suspension rattle thunk/thump. This may help isolate where to look.

I don’t have the car anymore. It was metal against metal rattling sound.

[T_R]

Originally Posted by dubb13

That is some bullshit they would have to fix that how is it the dealer didn't hear that I meant it's pretty consistent did you consider taking it to a different dealer or call corporate and see if they can get you to dealer and open up a complaint because that's unacceptable

They get one more shot — if they can’t fix it with the video of the constant noise, I give up. There are other BMW dealerships in NJ.