Two problems related to crankcase (pcv) have been reported for the 2002 BMW 325. The most recently reported issues are listed below.
Vehicle was burning a quart of oil every 800 miles. Compression test and leak down test showed 220psi. Technician suspected crankcase vent valve. Replaced crankcase vent valve.
BMW 2002 325xi at low temperatures like 5 or 6 f. The crankcase vent valve froze and the high pressure built up caused the valve to blow and couple of gaskets burnt. Oil spilled over to the exhaust causing smoke coming out of the engine compartment. If driven couple of more miles the car would have been on fire. The car just has 67000 miles which is fairly low miles and new car. All the mechanics I talked to quickly recognized the problem and asked me not to drive at all. They said it can catch fire if driven little more. Its a common problem that most of the mechanics recognize and frequency is high but in cold states not in warmer states.