Two vent lines in the pcv system

Knifeedge2k1 · 12-08-2020, 03:22 AM

There are two vent paths in the pcv system on the B series engines (compared with one line in most other engines including the N series)

https://bimmercat.com/bmw/en/search/...0i/ECE/11_7808

All the oil catch can kits available (BMS, ECS, Turner, Mishimoto, etc.) only splice/intercept the larger of the two lines. Anyone know what the smaller line does and why the oil catch can manufacturers don’t bother with it ?

Knifeedge2k1 · 12-08-2020, 06:25 AM

Looks like the second line is for fuel breather system

JD11937 · 12-11-2020, 10:51 AM

Speaking off breathers. Anyone see a down side to this?

https://vargasturbo.com/product/vtt-...case-breather/

12-08-2020, 03:22 AM	#1
Knifeedge2k1 Second Lieutenant 153 Rep 280 Posts Drives: BMW G30 520i 2019 Join Date: Aug 2020 Location: Hong Kong iTrader: (0)	Two vent lines in the pcv system There are two vent paths in the pcv system on the B series engines (compared with one line in most other engines including the N series) https://bimmercat.com/bmw/en/search/...0i/ECE/11_7808 All the oil catch can kits available (BMS, ECS, Turner, Mishimoto, etc.) only splice/intercept the larger of the two lines. Anyone know what the smaller line does and why the oil catch can manufacturers don’t bother with it ?
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12-08-2020, 06:25 AM	#2
Knifeedge2k1 Second Lieutenant 153 Rep 280 Posts Drives: BMW G30 520i 2019 Join Date: Aug 2020 Location: Hong Kong iTrader: (0)	Looks like the second line is for fuel breather system
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12-11-2020, 10:51 AM	#3
JD11937 Second Lieutenant 130 Rep 274 Posts Drives: 2017 M240xi Join Date: Aug 2018 Location: East Hampton, NY iTrader: (0)	Speaking off breathers. Anyone see a down side to this? https://vargasturbo.com/product/vtt-...case-breather/ Attached Images
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