I had the BSH can and block off plug for a while, and I seafoam every 3,000 miles. The seafoam seems to help a lot, the car runs noticeably better after I run it through. The catch can just got annoying after a while. Plus, it smelled terrible (common problem with the BSH cans) so I couldn't even park the car in the garage .
BSH can and a turkey baster to clean it out on a regular basis. Don't get as much oil as I expected. Biggest problem is the water content. have to clean it about once every two months this time of year.
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2007 MCS Laser Blue 2010, 2008 BMW Oktoberfest Autocross - Stock Mini First Place
2009 BMW Oktoberfest Autocross - Stock Mini Second Place BMW CCA Driving Instructor/Engine Mechanic/Speech Recognition Specialist
I have a BSH can as well in my 08MCSa. The newer ones have a dipstick that gives an access point for siphoning out. Through the winter I was getting 4-8 oz of water plus a bit of oil every week. Warmer weather drops that to 2-4 oz per week. I have no odd smells. I don't know if it really helps reduce carbon buildup or not, but I figure that getting this trapped can't be a bad thing. I have the block off plug as well. I can get pics if you want, pretty simple install.
The install is super easy if your car is stock otherwise. I had the ALTA intake and M7 J-brace so I had to mount it on the other side of the engine bay (see pic). The longer the hoses you use, more oil vapor will fill the bottom of the can. I was emptying it almost weekly in the winter.
