-actually the hoses should be fine now as I have changed them to heavy duty hydraulic hoses.
-I was planning on more frequent catch can changes this winter.(I will be keeping a close eye on it.)
-my exhaust right now after the hydro lock is still burning out the old oil from exhaust so probally won`t pass emissions ,but in northern ont we don`t have any testing up here.(I`m not losing oil)
-for pulling combustion gases past the rings ,I don`t mind taking my chances on it ,compared to a totally failed engine. at least now I can keep an eye on it and theres no way oil can get sucked up from the dipstick tube into the intake.

Ok I always thought both the head and block needs ventilation, not meaning venting to atmosphere but vacuum to put out gases. My old honda and Audi both had the head and block running to a Y connector then into the oil catch can then to the intake manifold with a check valve inline. Almost everything I'm seeing online on running a catch can on the m54 doesn't show anything about a vacuum line connected to the block

the BMW M54 is a different breed of engine though?

I know the m54 is different but I thought all engines no matter what type need to have vacuum to pull out blow-by from the head and block

I can`t answer the question as I`m not the designer of this engine, so I don`t know how they work 100%, I know from reading you can`t use a vented catch can as it causes piston ring flutter , and must use a non vented catch can.

The block and head are interconnected through the timing chain/belt cavity on most engines. I don't want to say all, since I've not seen all of them. With that said, it is better to remove as close to the source as possible and multiple points have less restrictions.

Ok I saw a video on YouTube and the guy took the line coming off by the vanos and ran that to a catch can and back to the intake manifold

reason for me putting catch can on I live in canada where it gets very cold, and even putting a new ccv system in, there is still a possibility of a failure. just because of the hose thats connected to the oil dipstick. If I lived in arizona I wouldn`t even worry about it as much.

I think ring flutter is when the head has more vacuum than the crankcase

well were starting to get into the cold weather months and i`m starting to see some water and mayo in the catch can and oil fill cap. reason being is I only drive 15 min to and from work. I might try driving once a month for an hr and half to heat up the engine and get rid of the moisture these engines produce. this weekend coming I will empty my catch can as it is a 1/4 full of water and sludge. by the way I have 207000km on the engine, so about 2000km on the catch can and engine is purring away with no codes .