So the Pierburg pump is the smaller diameter (comes with adapter for the stock hanger) to fit the Delphi hanger BUT shorter so the hose wouldn't be quite long enough! So I installed the Pierburg pump in the original hanger with the included adapter, fixed up and reinstalled the original harness connector and installed that. Works well, nice and quiet, BUT doesn't hold pressure at all as if there is no check valve! I have a OE BMW pump and hanger in my cart and I think I might just pull the trigger on that and then keep the either keep the Pierburg as a spare or return that one too and maybe put a Bosch pump only into the original hanger, haven't made up my mind yet! Geeze!

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1988 325is (purchased new) sold
2004 X5 3.0 2005 X3 2.5
2008 X5 3.0 (new to me)