My 2018 M3 LR AWD just turned 100k miles, the oil pump is making a strange sound from the rear DU when it’s preconditioning on cold days (coldest we’ve had is 25˚F so far this year) I don’t remember it making that much noise or uneven noise last year. I’m not in a great spot to spend the diagnostic money if they’re just going to tell me it’s fine.. anyone have experience with this?