Yep - anything rotating that's out of balance will typically cause increasing vibration as RPMs increase. Something that causes vibration at only low RPMs is either something that stops turning at higher RPMs, or an issue with an engine mount, which only transmits low-RPM vibrations through the engine into the chassis. That's why I still think this is engine-mount related.

This problem started when the zener changed his driveshafts so that might be a clue. A driveshaft that is a hair to long or possibly binding just a bit could be a problem.

OK, sorry I think I am getting zone5 and Zener mixed up! ;)

I changed my engine mounts. It didn't really help.

Like I said, there are numerous stories of the mounts being replaced and it didn't matter. Two separate mount installations for me in 30k miles and zero difference.

I just ordered a new ECU with a 900 rpm idle and when I install it I will report back. It would be nice to find the root cause but I think that would probably involve a full effort by the BMW engineering team.

900 RPM is really fast, maybe try lowering the RPM to 500 or 550. A big problem with these threads is that everyone has a different idea of what is a vibration, mis(fire), buzz, hesitation, bog, noise etc. so that adds to the confusion and getting to the root of the issue.

Vibration is worse at lower rpms. This is a problem on many, many M54 engines, strangely doesn't appear to affect the V8s.

There are threads all over the internet for this problem and no one has solved it.

https://xoutpost.com/bmw-sav-forums/...ss-online.html

Are you sure you don't have a miss or weak cylinder? What are you using for scan tool? Have you done a compression test? Have you eliminated rotating elements? Have you tried to feel for vibrations in the engine bay? Did you check the driveshafts or for any other possible mechanical (maybe exhaust) transfer? You have lots of clues and things you could check but it seems you don't want to or are too lazy to follow any of them.
Have you tried lowering the idle RPM or are you just saying that it's worse ?

It's fascinating that someone will call another person lazy from the comfort of their chair, behind a screen, when that person would never, ever do that in person for fear of getting punched in the face, or worse.

Just an observation.

Not going to answer your questions -- don't interact with people like you.

Yeah, that sounds about right.

Of course I am the lazy one because I am sitting at the computer instead of actually working on YOUR car. That is fascinating. How old are you ?