Awful rattling noise from the front side

[constantin.c]

For few days I have an aweful noise comming from the front side of my Z4 (E85, 2.0i, 2006).

Following a video (4th to 6th second and 14th to 15th second):
[youtube]Zcbnh-OzkLs[/youtube]

http://www.youtube.com/watch?feature=player_embedded&v=Zcbnh-OzkLs

Does anybody have an idea what this could be?

 

[constantin.c]

It appears only at approximately 1000 cycle/min. It does not matter if I start to drive or brake down with 3rd gear and accelarate again.
With more revolutions the noise is not there.