My car also have been shaking from the day one only when the engine on and not running :thumbsdownex at traffic light, but nothing else while it runs ). I don?t know, but may be the engine oil could cause the noise on your cars. I read in different sites about motor oil qualities or characteristics and some of them could create this kind of noise.
I check with my dealer and they use Castrol SLX long life for all series except M series where they use Castrol RS (racing), and for the all models they use castrol GTX (the worse one). Thely also told me once after they changed motor oil to a 545 (by fortune it wasn?t my car), and because a that time they dind?t have Castrol SLX, they used Castrol Racing, and that car had had this kind of noise till after 10M miles they changed de the motor oil and... THE noise HAS GONE!!!!!! Obviously that time they used Castrol SLX. Do you think could be the answer for the noise you were talking ?

 

All quite at 23K miles.

 

BMW replaced my engine last November after removing one of the cylinder heads and finding scoring in more than one of the cylinders. Andy545 also had his engine replaced. They tried the valvetronic levers route first, with no success (obviously since the FSE wanted to try replacing the heads next), ultimately BMW caved once it was apparent there was serious damage inside the engine. You need to get them to remove one or both of the heads to check for scoring in the cylinders. Be persistent, this is not a "normal" noise. They tried that one on me too, several times, and finally the service manager agreed he did hear something clattering on one side of the engine. I believe it was the passenger side.
Good luck.

PS I pointed them to this board for verification that there are many others who experience this issue.

 

Please read my post. I had an issue when this happens at cold start. There is a service bulletin about this.

Read this thread!!!