One problem related to crankcase (pcv) has been reported for the 2012 BMW 328. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 BMW 328 based on all problems reported for the 2012 328.
Without warning and no obd2 codes thrown, my car and many others in the e90 (2007-2012) 3-series (n52 engine) will stall, lose power, and/or burn excessive oil when the integral pcv - valve cover starts to clog. Many owners on the BMW boards online have reported similar problems. The e90 3-series Bmws have an integral, internal positive crankcase ventilation system as part of the engine's plastic valvetrain (engine cover or valve cover) cover. Inside the valve cover is a series of cyclones that separate the oil from the valvetrain gasses and route the gasses to the pcv system. Repair is > $4000.