[parksjm7]

Preface: I'm learning about how PCV works in general and am looking for feedback and help from the community to improve my setup.

I've had a BMS catch can fitted the way it was intended to by the PCV flapper valve but not catching any oil (I rarely push the car lately), so I read up on how to route the Vacuum side PCV and gave it an attempt to adapt the BMS unit for the vacuum side.



^Sourced some 12AN ID (~.695" inside diameter) hose and 8AN male to 3/8" barb fitting for the OCC outlet.



^ AD fitting with both O-rings transferred and oiled.



^ Sourced an 8AN female to 3/8" barb fitting to fit on top of the AD fitting; I didn't think about the fuel rail clearance issue. While I was able to fit it, I did not like how the fuel rail was touching the metal fitting.



^ So I wound up using the 8AN hose to connect from the AD fitting to BMS CC inlet for now; I'll probably be sourcing two more 3/8" barb to 8AN male fittings to connect the end of this hose to the CC inlet.



^ As far as I understand, the Vacuum side PCV should be more finely filtered versus the Boost side PCV which favors flow. Since BMS is known to be a high flowing can, I put in a tiny bit of steel wool between the double baffle. Thinking of sourcing Copper wool or stainless steel wool in the future for this purpose.



^The OCC outlet with the 3/8" barb fitting will be connected to a 6AN ID hose, which will be hooked up to a 3/8" barb fitting vacuum tee, hooked up to the fuel EVAP line connected to the intake manifold.




^ Updated after install; Vacuum tee is fitted on the 6AN hose then to the EVAP line, then used ziptie to secure for the time being. I found it easiest (without a heat gun) to dremel the stock EVAP hose down the middle then using a plier to roll back the shrinkwrap-like plastic material.



^ Done.
- Flapper remains stock back to rear turbo inlet
- PCV valve is deleted with AD PCV fitting, connected by AN12 hose to BMS CC inlet
- CC outlet connected via AN6 hose to intake manifold EVAP line via vacuum tee

As I said in the preface, I'm looking for help and advice from the community on how to improve my vacuum side PCV setup and hopefully contribute what little I can. Any guidance is appreciated!

Update 1:

Prior to this setup, I had some smoking on my bank 2 exhaust for cylinders 4-5-6 which lingered for a good amount of time after shutting the engine off. In the 2 weeks that I’ve driven the car with the PCV delete + vacuum side catchcan, I haven’t seen this smoking happen even once. There’s a chance that it may be unrelated / coincidental / due to recent temperatures, but judging by where the vacuum side PCV function would normally dump blowby gases when using the stock PCV setup, I’m thinking that my old PCV valve or PCV intake port(s) are clogged or otherwise not functioning as intended for bank 2, and that by deleting the PCV valve and bypassing this path to the intake PCV ports cured the smoking, as oil from blowby is routed to the catchcan, filtered, then to the intake manifold directly. I’d appreciate other readers’ feedback on this theory.

Also, this may be placebo, but it feels like the engine has "cleared its throat" in its operation as I feel less hesitation and bog in low-mid load operation.

E90post Credits:
http://www.e90post.com/forums/showthread.php?t=1231974
http://www.e90post.com/forums/showthread.php?t=518306

[Boland01]

I've got the BMS OCC like yours on the high side and Mitsubishi OCC and BMS adapter kit pnp on the low side. The low side picks up most of the oil on my car compared to the high side too. Keep us posted on how your set up works out.

[Tim603]

Hey whats up with that silver AN fitting, does that have a check valve in it? If not you will pressurize the crankcase when you hit boost.

Other than that, the steel wool is not needed. The orifices within the valve cover are small enough to restrict the airflow (acting as a bottleneck) as intended. I wouldn't risk clogging up the system with that steel wool.

[parksjm7]

Originally Posted by Tim603

Hey whats up with that silver AN fitting, does that have a check valve in it? If not you will pressurize the crankcase when you hit boost.

Other than that, the steel wool is not needed. The orifices within the valve cover are small enough to restrict the airflow (acting as a bottleneck) as intended. I wouldn't risk clogging up the system with that steel wool.

Thanks for your feedback - here is the link to the fitting:

http://www.ad-eng.net/store/p22/AD_E...e_Fitting.html

I dont' fully understand the routing in the N54 PCV, but here is the description of the fitting:

"This fitting replaces the factory PCV fitting in the valve cover and provides two main functions. First, it blocks off the passage way to the intake manifold keeping your intake valves cleaner; a great alternative to removing the valve cover plugging the head. Second, it provides an additional crankcase vent "

So no, I don't believe it has a check valve, but will draw vacuum from the intake manifold to attract blowby during idle / low load is my understanding; I believe the high-load or boost side with the Flapper routed back to the rear turbo inlet manifold is kept stock. Based on the seller's description, do you feel that the crank will still be pressurized upon boost?

[Tim603]

Originally Posted by parksjm7

Thanks for your feedback - here is the link to the fitting:

http://www.ad-eng.net/store/p22/AD_E...e_Fitting.html

I dont' fully understand the routing in the N54 PCV, but here is the description of the fitting:

"This fitting replaces the factory PCV fitting in the valve cover and provides two main functions. First, it blocks off the passage way to the intake manifold keeping your intake valves cleaner; a great alternative to removing the valve cover plugging the head. Second, it provides an additional crankcase vent "

So no, I don't believe it has a check valve, but will draw vacuum from the intake manifold to attract blowby during idle / low load is my understanding; I believe the high-load or boost side with the Flapper routed back to the rear turbo inlet manifold is kept stock. Based on the seller's description, do you feel that the crank will still be pressurized upon boost?

Did you have to pull out the factory PCV valve (see pic below) or did it just stay in there? If it stayed in there you are good, that has a checkvalve in it. If you removed it, that unit you bought should have a check valve. You can tell by blowing into it. One way the air passes through, the other way the air is blocked.

Basically, since you are tapping into the throttle body for vacuum, when you hit boost the throttle body becomes pressurized, no longer pulling vacuum through your catch can, instead it tries pushing air the other direction. When the check valve is in place, as soon as this start happening it closes the valve stopping that air from entering the crankcase pressurizing it.

[Tim603]

I just saw your new photos, it looks like where you tapped into on the throttle body, evap line, there is a check valve right there, so you should be good.

[parksjm7]

Originally Posted by Tim603

Did you have to pull out the factory PCV valve (see pic below) or did it just stay in there? If it stayed in there you are good, that has a checkvalve in it. If you removed it, that unit you bought should have a check valve. You can tell by blowing into it. One way the air passes through, the other way the air is blocked.

Basically, since you are tapping into the throttle body for vacuum, when you hit boost the throttle body becomes pressurized, no longer pulling vacuum through your catch can, instead it tries pushing air the other direction. When the check valve is in place, as soon as this start happening it closes the valve stopping that air from entering the crankcase pressurizing it.

The AD PCV delete fitting is a straight-through piece without any check valves built in; and thanks for the confirmation on the evap line check valve - I tested it when I was installing it by blowing air into it and had the arrow indicating it'll flow one way

[BOosted 335i]

The black oring that you reused with ad fitting,was that black oring from the stock plastic piece that you removed?

[parksjm7]

Originally Posted by BOosted 335i

The black oring that you reused with ad fitting,was that black oring from the stock plastic piece that you removed?

yes, from the stock pcv valve.