Ninja_Zx11 - In your other thread when you first documented the issue, you said that you had vibrations at idle and when driving at certain RPMs. Now you don't appear have it at idle anymore - is that correct? If so, did changing the engine mounts solve the idle problem but not the driving rpm vibrations?

I am going round in circles trying to find the cause of mine and I keep coming back to engine mounts. When I bypass my engine mount vac solenoid and connect the mounts direct to a constant source of vacuum, I get no vibrations while driving - it's like a different car completely. But at idle it's the same.

My vac system appears to be working to spec according to BMW who 'said' they tested it. My own test of just checking for vacuum when revved did show that there is vacuum when revved so it's working to an extent definitely.

soooo, why does giving the mounts constant vacuum make the car drive better in all rpm's except idle? I can only guess that my mounts have deteriorated to an extent that when in the soft state, they are not performing adequately. When hard they do their job and so having them hard all the time (while not how BMW intended) produces less vibes than having them soft upto 1050rpm. Perhaps the idle rpm is just too low for hard mounts to overcome those vibrations

I went and tested another 2011 with identical mileage (40k) today and at idle the steering wheel had the same vibrations but when driving it felt 'smoothed out' and much less vibrations than mine. This has just got me thinking that maybe these mounts are starting to deteriorate at this mileage.