What is this noise

[LazyEyeCrazyI]

1989 325i
Watch the video here.
The "mechanic" returned my car sounding like this after I had the head machined and the head gasket replaced. This sound was not there before I took it in.
They tried telling me that they think my car was in a junkyard before, and that it was done for from the beginning. SO nice. I'm so tired of getting fucked over by mechanics, excuse my language.

I had it towed to a BMW specialist, who says I need to either replace or rebuild the entire engine. More bad news, anyone?

I've been told "worn camshaft," "piston slap," "valve adjustment," "exhaust gasket," and much more. I want to know if anyone else has any more ideas or what diagnosis they agree with more.

[LJ851]

That is the sound of chartreuse coolant hoses.

[LazyEyeCrazyI]

lol I actually didn't start that green tradition. It came with the green hoses and washer fluid reservoir when I bought it, and I liked it so I painted the valve cover and intake manifold cuz I like green. ;)

[MOOK]

sounds to me like a valve or rocker, id start by pulling the valve cover and checking the rockers for excessive play or damage (rotating the engine to top dead center for each cylinder before checking)

[AndrewBird]

Sounds like it needs a valve adjustment. Definitely pull the valve cover and inspect though, could be worse.