Thanks for all the posts.

I edited the prior post of video links to provide context.

The smoke is definitely not water vapor. I am fairly certain it’s fuel vapor. When I ran it for 15 minutes, the exhaust tips were wet with what smelled like gas.

The oil separator is brand new – purchased from The BMW Part Store and appeared to be Genuine BMW. While pulling the intake, the old oil separator came right out in my hand after I undid the two bolts that hold it in. The larger of the two hoses that come from the metal pipe at the back of the passenger side of the motor, which connects to the bottom of the oil separator, had disintegrated – there was a small amount of burnt oil on the coolant crossover pipe nearby. The smaller of those hoses – the one that goes underneath the intake manifold and attaches to a port on the inside of the EGR (which is also brand new) – had also disintegrated. I replaced both hoses with new.

I’ve started the car maybe 6 times. In the video, the car had not run for a day, and as before the smoke starts out light but quickly gets heavy. When I’ve restarted the car within a short period of time, it smoked heavily right away. The heaviest was after I tested the injector harness with the noid light. I hadn’t disabled the fuel pump. That’s part of what made me think injectors were stuck open. I believe this means there is a ton of fuel dumping into the exhaust. When the car sits it evaporates.

The valve cover gaskets are brand new. There was oil in the passenger side plugs. I sopped it up before changing plugs. Pretty sure the car has run enough to burn off any oil that may have gotten into the combustion chamber.

I also replaced all coolant hoses. There is no coolant leaking anywhere. To change the valley pan I removed the coolant crossover pipe at the rear of the motor. Used new gaskets on reinstall.

It is lower on oil than where I remember it being, so maybe it is sucking too much oil into the intake. I’ll research oil separator issues – “found” this video suggesting it might be the problem: https://www.youtube.com/watch?v=s8irMmWvWfw. I’ll also pull the oil fill cap – I assume the expected result is suction and rough running. I’ll also pull a few plugs to see what they look like.