[Acheron83]

Got my parts installed. Took about 3 weeks to get to the dealer.

[RoundelM240]

Got my car back yesterday right before noon. No more thump-over-bump syndrome, and they checked everything else on the car while they were at it. Both rear strut mounts were replaced as was the stabilizer bar and its mounts. It took a bit of cajoling to get the service dept. to agree to do this, but they did order the parts in advance and I got my car back 2 1/2 days later. An optimal outcome all the way around!

[J-RO]

Originally Posted by RoundelM240

Got my car back yesterday right before noon. No more thump-over-bump syndrome, and they checked everything else on the car while they were at it. Both rear strut mounts were replaced as was the stabilizer bar and its mounts. It took a bit of cajoling to get the service dept. to agree to do this, but they did order the parts in advance and I got my car back 2 1/2 days later. An optimal outcome all the way around!

Welcome to the club. Feels like a new car.

[Maccam26]

Originally Posted by ZTK_M240i

I think at some point during the '25 build (around April/May) they swapped the parts for production.

I have a '25 with a late May build date, and my friend has a '25 with a late April build date. I have about 1500 miles on mine, he has over 2500, and neither of us have the rear suspension thumping noise as of now.

My car is a May 2025 build and 1600 miles, been hearing it almost since brand new. Finally taking it in Tuesday to have it looked at.

[PNTDG42]

I’m glad it’s been fixed but honestly I still have questions lol. It’s such an odd situation and Ill never stop wondering exactly what was wrong with the original parts. And the stabilizer bar being done too, makes me even more curious.

[RoundelM240]

Originally Posted by PNTDG42

I’m glad it’s been fixed but honestly I still have questions lol. It’s such an odd situation and Ill never stop wondering exactly what was wrong with the original parts. And the stabilizer bar being done too, makes me even more curious.

From what I've been able to determine, the parts in question were sourced from Asia and were not up to the standards BMW required. For whatever reason, the assembly plant in San Luis Potosi was unaware of this discrepancy and continued to build with the defective parts until the problem was discovered.

[GLudan]

I took delivery of my ’25 M240i in July and noticed the sound the very first time I drove it. After doing a bit of searching on Bimmerpost, I saw that others were experiencing the same issue. I brought the car to the dealership, mentioned the problem, and provided them with SIB #33 01 25. The lead technician was already familiar with it and confirmed the issue after a test drive.
They ordered and installed the necessary parts, and I couldn’t have been happier when I finally drove it home and the rattle was completely gone. I’m posting the receipt in hopes it helps someone else dealing with the same problem. Cheers!

[curtdragon]

Originally Posted by GLudan

I took delivery of my ’25 M240i in July and noticed the sound the very first time I drove it. After doing a bit of searching on Bimmerpost, I saw that others were experiencing the same issue. I brought the car to the dealership, mentioned the problem, and provided them with SIB #33 01 25. The lead technician was already familiar with it and confirmed the issue after a test drive.
They ordered and installed the necessary parts, and I couldn’t have been happier when I finally drove it home and the rattle was completely gone. I’m posting the receipt in hopes it helps someone else dealing with the same problem. Cheers!

Strange. Got mine done beginning of June and I didn’t have the issue.

[ZTK_M240i]

Originally Posted by curtdragon

Strange. Got mine done beginning of June and I didn’t have the issue.

...and I got mine in the middle of July and no thump.

It's crazy how cars can be built during the same period, and some make the noise and some don't. If it was a defect with a part, you would think they all would do it.

[phileaglesbmw]

My 26 M240i built in mid Oct makes the thump. Im having Icon Locklear coating put on it Jan 5th-6th so probably be late Jan to have dealer look at it.

[m36]

This has probably been posted in this thread before, but this is the official BMW USA info about the noise: https://static.nhtsa.gov/odi/tsbs/20...17505-0001.pdf

[ZTK_M240i]

Originally Posted by phileaglesbmw

Im having Icon Locklear coating put on it Jan 5th-6th .

Man, all I can say is do your research on that stuff in the detail forums and Reddit. Personally, not a fan as there are too many possible issues.

If you must do it, make sure you have an super experienced installer who has a spotless place to apply it, or you will not be a happy camper.

[R710]

My car also making that rear thump sound

July 2025 build

[phileaglesbmw]

Originally Posted by ZTK_M240i

Man, all I can say is do your research on that stuff in the detail forums and Reddit. Personally, not a fan as there are too many possible issues.

If you must do it, make sure you have an super experienced installer who has a spotless place to apply it, or you will not be a happy camper.

I know a good experienced installer.

The reddit post is supposedly a detsil business in CA but there is no record of his company otherwise. I've had it for a year on our X5 and it is great. It is more durable than any ceramic coating which will not last near as long. It also self heals minor scratches in the sun.

[Mech Spec]

I read through that reddit post, its crazy how its so easy to find. Seems super sus (the reddit post)

Im definitely interested in a coating better than ceramic and not ppf.

[R710]

Update: Called my dealer on Monday and explained the thump noise, and mentioned the service bulletin. They booked me in for Wednesday, and by Friday morning the car was ready.

They replaced the mounts only.

What a huge difference! The car now feels noticeably smoother, and that annoying thump is completely gone. Very happy with the result
Build date: July 2025

[p_li]

I hoped I would never come back to this thread, but...

In the original repair (link) they only replaced the shock mounts with the ones specified in the SIB, they didn't replace the auxiliary shock absorbers nor the stabilizer with its supports. The problem seemed to be resolved until the harsh winter in Poland right now, I could hear the sweet old thump again.
I'm trying to gather as many arguments as I can to convince BMW to replace the remaining parts. Has anyone possibly had similar experience?

[RoundelM240]

When I had my repair done, they included the aux shocks and the stabilizer. I'm in the US, though, so that may have something to do with the differences in your repair.

[frank gel]

Its the struts. BMW will replace them if the car is under warranty.

[m36]

Take one rear wheel off and take a look at the sticker on the shock absorber, is the part number "6894637 A 02"? 01 would be an older version.

[hooked]

Originally Posted by p_li

I hoped I would never come back to this thread, but...

In the original repair (link) they only replaced the shock mounts with the ones specified in the SIB, they didn't replace the auxiliary shock absorbers nor the stabilizer with its supports. The problem seemed to be resolved until the harsh winter in Poland right now, I could hear the sweet old thump again.
I'm trying to gather as many arguments as I can to convince BMW to replace the remaining parts. Has anyone possibly had similar experience?

I had the full "SIB 33 01 25" done to my 2022 in July 2025. Noise went away. Great.

But, after I put my winters on and the temps dropped, I started to hear it again, but not as consistently as before.
Now I'm questioning whether this fix is 100% or just as good as it's going to get, and came here too and saw your post...

Owning this car has been a love/hate thing. Love the way it drives, and it has never left me stranded, but I hate the amount of stuff I've had to replace under warranty (that I've never had to replace on any other car I've owned), which makes me think I probably don't want to own it afterwards.

Lots of unusual stuff here...
Rear shocks (before they knew what was causing the thump)
Headlights that won't clear condensation
Front brakes and rotors (warped)
Rear suspension bits under the SIB
The vehicle's battery (I just picked it from BMW today...yup, it went south around the 3-year mark)

[phileaglesbmw]

My Oct 2025 build M240 xdrivr has been doing it since right since new. I noticed it on a drive with around 500 miles on it. I had a couple surgeries since Aug so I'm finally getting it in Thurs. Dealer didn't seem to know much about the problem but I mentioned about the SIB. It sounds like it is coming from the right side, a hollow like sound, below 40mph on any kind of bumpy roads.