Oil Separator Replacement/Cleaning Interval?

[lemoose]

Mine at 178k miles. oil changed every 6k miles since i took ownership (119k). Brakleen and pipecleaned it through as above

[PSUEng]

Bumping this thread with a few questions, thanks to all who contributed; great info and really helping me out while investigating this. I can't say I'm having any issues at the moment warranting replacing these parts, but I'm at 82.5k miles and the PCV seem easy enough and inexpensive enough to replace to avoid any issues down the road due to inadequate ventilation. So, here's what I'm curious about:

1) Is the VAICO branded PCV acceptable here? Big price difference compared to Genuine. But everyone knows this game, sometimes it's good, sometimes not.
2) Is it normal to have a small mount of oil residue in the 11157831311 breather hose between the PCV and intake manifold? Not sure if this one would still be good, or warrant replacing in addition to PCV (if not broken, clean with brake cleaner?)
3) Similar question as above, but regarding the 11617831930 that connects between the intake manifold and dipstick. Can this piece clog, or are the internet vendor "Kits" with this part included just pushing sales? I'm not sure what is carried in this tube (air, or oil vapor?)
4) Regarding cleaning the passageway on the valve cover between the PCV and oil return line, is there a risk of sludge being leftover and clogging up the banjo bolt/oil return pipe? I ask out of ignorance about how much oil is actually flowing through the passageway and pipe--just hot residual, or an actual flowing amount, etc.
5) Looks like cleaning the passageway can be done with the valve cover installed, just to confirm.
6) Is removal of the PCV as easy as unbolting it, and pulling it out (unseating the grommet/sealing ring)? FCP and ECS recommend changing the valve cover gasket here and I can't seem to understand why unless you need to confirm proper grommet seating on the inside of the cover, or???

[bigjae46]

I’ve cleaned the return line, typically cleanish oil came out.

Normal for some oil to be in the crossover tube to the intake manifold, bottom of the intake, and in the tube to the oil pan. If there’s a big puddle in the intake manifold…that’s a problem.

[y2k_o__o]

Bumping this thread with a few questions, thanks to all who contributed; great info and really helping me out while investigating this. I can't say I'm having any issues at the moment warranting replacing these parts, but I'm at 82.5k miles and the PCV seem easy enough and inexpensive enough to replace to avoid any issues down the road due to inadequate ventilation. So, here's what I'm curious about:

1) Is the VAICO branded PCV acceptable here? Big price difference compared to Genuine. But everyone knows this game, sometimes it's good, sometimes not.
2) Is it normal to have a small mount of oil residue in the 11157831311 breather hose between the PCV and intake manifold? Not sure if this one would still be good, or warrant replacing in addition to PCV (if not broken, clean with brake cleaner?)
3) Similar question as above, but regarding the 11617831930 that connects between the intake manifold and dipstick. Can this piece clog, or are the internet vendor "Kits" with this part included just pushing sales? I'm not sure what is carried in this tube (air, or oil vapor?)
4) Regarding cleaning the passageway on the valve cover between the PCV and oil return line, is there a risk of sludge being leftover and clogging up the banjo bolt/oil return pipe? I ask out of ignorance about how much oil is actually flowing through the passageway and pipe--just hot residual, or an actual flowing amount, etc.
5) Looks like cleaning the passageway can be done with the valve cover installed, just to confirm.
6) Is removal of the PCV as easy as unbolting it, and pulling it out (unseating the grommet/sealing ring)? FCP and ECS recommend changing the valve cover gasket here and I can't seem to understand why unless you need to confirm proper grommet seating on the inside of the cover, or???

Removing the PCV is super easy, just need do unbolt the five 10mm bolts. Everything is exposed. No need to remove valve cover, coil or anything.

I purchased the VAICO PCV (along with the Genuine BMW o-ring 34x4mm) because it's not a rotating mechanical nor electrical parts, so I think OE replacement parts should be fine. So far I am on the 3rd week and no issues have been seen.
Meanwhile, I also replaced the broken air return hose at the same time.
I am keeping my OEM PCV and brake-clean it when I have time, and in case I need it urgently.

check out my E46 Fanatic restoration post: https://www.e46fanatics.com/threads/...#post-19140850

Will keep you all posted

[y2k_o__o]

to OP, what symptomes do you have when the valve cover oil passage is clogged?

[heinzboehmer]

to OP, what symptomes do you have when the valve cover oil passage is clogged?

Nothing that affected how the engine ran. Just found oil in the airbox and noticed that the separator was gunked up, as mentioned above.

[y2k_o__o]

Nothing that affected how the engine ran. Just found oil in the airbox and noticed that the separator was gunked up, as mentioned above.

if clogged, wouldn't it force all the oil fume into the air box and into the combustion chamber?

[heinzboehmer]

if clogged, wouldn't it force all the oil fume into the air box and into the combustion chamber?

Yep