2004 4.8iS Bottom End Motor Knock

[BimmerE38E53]

Hi All,

So when I bought my X5 it was not apparent to me that there was a knock on startup. It's still fairly faint but it sounds deep!! By deep I mean bottom end. Not like a lifter tap. The strange thing for me is that it goes away after it has warmed up. Seems almost like the oil send unit or something may be getting slack. But that is a pure guess. I'm not very experienced with this motor but it's a very distinct sound that I have never heard before. Motor pulls extremely strong and runs solid. After it has warmed up its nice and quiet. Here is a small clip hopefully you can hear it. Trying to find some input on where to look to resolve this issue. I need to do the dreaded valve stem seals sometime this year and would like to fix this issue in parallel.