what i am reading , x5 question should be discussed by mechanics and other x5 users , previous or current . that would stop a lot of distraction , now listen , the x5 e53 has two and actually three fuel pumps, one : in the tank , fuel delivery pump , second the small dosage pump for your auxiliary heater , webasto , third and most important if go wrong is the high pressure fuel pump 2.5 bars if i remember right which sits left hand side of engine in the middle and is a pig to get too ! so i hope that helps some of you