Excessive back pressure (plugged filter) can cause more noise too, so something to consider if the problem persists. The syphon jet being restricted could be a problem as well but then the rail pressure would increase as well. Hopefully the replacement fixes the problem though.

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