Well, wow. Roadside assistance?
Wish I knew that when we replaced the original Valeo Alt in our 07 550i in 10/19. Bought a used factory Valeo unit online and it arrived with a cracked rear cover (I didn't notice.) Installed it and it was overcharging like a beast. Removed it and noticed the cracked rear cover, removed it to discover a cracked regulator. Ouch. Seller gave us a price break but we needed the car in the mean time. Installed the old regulator on the replacement alt and it was fine for months. Should have just let it ride but put a new Valeo regulator in it and it was acting up. I don't remember how we ended up but my son and I put that alternator in 3 or 4 times. Not fun in a V8 E60. Not a bit.
Link to my M50 engine rebuild thread
http://www.bimmernut.com/forum/showthread.php/43339-M50-Eng-4L30E-Trans-RRR-Far-More-Than-I-Ever-Expected?highlight=93+525+paul