Very understandable trying a knock off. OE on that part is stupid expensive.

Somebody gave me a SAP from a 7 series and it took very little work to modify to fit. Just got rid of the eternal filter since the 7 series one has it built in. Gives you an option if you have a junk yard possibility. I had to drill a hole or two in the mounting plate as the pump is oriented like 60° different angle but it worked perfectly. I think the 5 series that era is the same part.

Good luck solving, it was a very noisy month or two before I got my SAP swapped. Suck on the double failure and the time to find but somebody is going to see the thread in the future and they will take 45 min. vs. 3 hours to diagnose.

Supposedly the bearing can be replaced vs. the whole pump but I couldn't figure out how to take it apart non destructively.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)