I remember the desecant bag inside the filter drier rupturing on an 87 325 I used to own. Send the large granules all thru the system where they plugged up the compressor's suction side due to a built-in screen. My 525 doesn't have a built in suction screen. It might be a long shot but you could have something similar going on.
JR
1992 525 IA, EAT chip, 16 x 7.5 Rondell 58's, BavAuto Springs, Bilstein Sports, Elipsoid Smileys & fogs, Z3 Pistol grip shifter, 4 VDO gauge package, Azure Blue w/nice patina - clearcoat shot