Hey, the cause of that noise is the vacuum pump.
Not sure if you ever figured it out, or have dealt with it. But I know for sure it's the vacuum pump. The video you put up saves me from having to put my own video up

I'm busy scouring the internet trying to find a way to fix the noise. I recently replaced the timing chain and sprockets on my X35d M57 engine, and when I started it back up for the first time, almost had a heart attack when I heard that noise. -Thought I'd gotten the timing wrong! But no, after trying a few things, I removed the vacuum pump, and the engine stopped making that noise.
It wasn't making the noise before I did the timing chain. So I'm assuming it's something done. I've tried reseating it a bunch of times. New Oring. Just not sure.

Hoping someone knows.

-Sim