2001 3.0 x5 170k

Changed oil just now and was letting car run to burn off the oil I spilled and heard this light random rattle. It's coming from top of engine but I can't honestly tell where. Kinda a weird not constant rattle and as engine ran it got less and less but didn't go away completely. Can't hear it really with hood down. I was like wtf is that? But then remembered hearing people talking about vanos rattles and such so I am curious.

I will check YouTube in a little while to see if there are any videos but first I need to rebuild my fence gate so figured I would post first to hopefully get some ideas.