[TJZ67201]

Originally Posted by J-RO

Does the G87 have the same problem?

To my understanding no. You cannot option the same adaptive suspension on the M2, its more stiff and track focused

At this point I am 95% sure the noise has the be coming from the adaptive dampers. I’ve done a lot of other troubleshooting and everything else seems solid

Edit:
Check user BoilerM posts, he seems to have the solution! Expensive, but maybe worth it IMO

[BMWM.D.]

Bringing this one back. I started the original “suspension thump” thread, and am a BMW tech as some of you know. I replaced both of my rear shocks and mounts, and the thump is still there. No service bulletins or Advanced Information on this that I’ve seen. I believe they all do it, and it’s more or less normal.

That said, I’m going to have to tear my rear shelf out to resolve what is likely the plastic vent vibrating against something. I’ve also had torsional creak noises from the shelf (like when going up a driveway sideways) for a while. Since I do this stuff for a living, my motivation level has been a little low as far as going after this. Think it’s finally time to dig into it.

[Littlecoupe]

Originally Posted by BMWM.D.

Bringing this one back. I started the original “suspension thump” thread, and am a BMW tech as some of you know. I replaced both of my rear shocks and mounts, and the thump is still there. No service bulletins or Advanced Information on this that I’ve seen. I believe they all do it, and it’s more or less normal.

That said, I’m going to have to tear my rear shelf out to resolve what is likely the plastic vent vibrating against something. I’ve also had torsional creak noises from the shelf (like when going up a driveway sideways) for a while. Since I do this stuff for a living, my motivation level has been a little low as far as going after this. Think it’s finally time to dig into it.

We appreciate your feedback on the project. I've personally had a lot of cold-weather expansion/contraction crackling going on from the rear of the car, to the point I think I may need to remove some things and add padding. It's getting a bit ridiculous as this point.

If you do remove the parcel shelf, I'm curious if you as a professional can confirm if there is no way to remove the shelf without removing at least the C pillars. Or, can you remove the left and right side leather pieces (on each side of the rear seats) to access the bolts holding the lower part of the C pillars, and then remove the C pillars without removing the rear window plastic side trim (big panels) to get at the rear parcel shelf?

I'd prefer to remove as little as possible if I can help it, but I do think I should pull out the parcel shelf and add some insulating material to the plastic vent on it.

[IanH]

Have we ruled out the floor of the trunk causing the thump? it happens when you go over bumps?

I've never heard it but I did notice when detaching my battery that it is basically not connected to the car in any way. I keep a loaded crate of detailing stuff in my trunk so that would probably stop it from moving.

[TJZ67201]

Originally Posted by IanH

Have we ruled out the floor of the trunk causing the thump? it happens when you go over bumps?

I've never heard it but I did notice when detaching my battery that it is basically not connected to the car in any way. I keep a loaded crate of detailing stuff in my trunk so that would probably stop it from moving.

Yes. Trust me I tried everything. Fully disassembled the trunk. And the undercarriage panels. Even thought it might be fuel filler neck or the gas tank. None of which were the culprit. I also created a whole tread about removing and sound deadening the rear parcel shelf. Also fully removed the rear seats.

My thump is now completely gone only after replacing the suspension.

EDIT: thought this was in the thump thread 😂 Either way, the thump is its own beast. I WILL ADD: the rear parcel shelf vent does cause some noise and creaking. After sound deadening, that was eliminated.

Edit 2: to add, to my knowledge you absolutely have to remove the lower door trim and back seat trim (as mentioned in my OP) as well as the C pillar. Those parts are all interconnected and I saw no way to work around that when I had my whole back seat torn apart.

[Littlecoupe]

Originally Posted by TJZ67201

EDIT: thought this was in the thump thread 😂 Either way, the thump is its own beast. I WILL ADD: the rear parcel shelf vent does cause some noise and creaking. After sound deadening, that was eliminated.

Edit 2: to add, to my knowledge you absolutely have to remove the lower door trim and back seat trim (as mentioned in my OP) as well as the C pillar. Those parts are all interconnected and I saw no way to work around that when I had my whole back seat torn apart.

Thanks for this. For the trim, I did see you mentioned you thought you need to remove everything to get to the parcel shelf. I was hoping there was some kind of trick...

That said, it would probably be better for me to take everything apart and add tape/padding to all plastic on plastic surfaces. It seems like every panel suffers from expansion and contraction noises especially in huge temperature fluctuations.

As for the parcel shelf itself, did you add any material between the vent and the shelf? When you said you added sound deadening, I don't recall if that was just the areas I saw in your pictures, or if that was also on the parcel shelf vent since that looks to be plastic on plastic as well. Mine definitely creaks if when you put pressure on it, but more annoying is the plastic-fork-cracking noises that are most prevalent when the car is left in the cold and then warms up. It lasts for about 30 minutes and then settles down, which is ironically the length of my whole commute...FFS.

[TJZ67201]

Originally Posted by Littlecoupe

As for the parcel shelf itself, did you add any material between the vent and the shelf? When you said you added sound deadening, I don't recall if that was just the areas I saw in your pictures, or if that was also on the parcel shelf vent since that looks to be plastic on plastic as well. Mine definitely creaks if when you put pressure on it, but more annoying is the plastic-fork-cracking noises that are most prevalent when the car is left in the cold and then warms up. It lasts for about 30 minutes and then settles down, which is ironically the length of my whole commute...FFS.

Yes, I used 2 different products for sound deadening. Kilmat metal stuff and some brand off Amazon foam sound deadener, I’ll paste the link below.

For the rear parcel shelf, I would recommend using only the foam. That is plenty to isolate and provide a barrier to prevent the plastic creaking against the metal. Just cover all the metal that you see once you have the shelf removed. Get as close to the rear window as you can.

https://a.co/d/3ZH3pot

This is not my original photo. But this is the area you wanna target, circled in red.