[darkhorse737]

The fuel pump is a common issue not only with bimmers. What are the main reasons for making this to happen?

...running your car constantly on low or on Reserve.

notice that the pump is made up of a small motor that drives the pump; and the motor runs on (composite) plastic bearings. the bearings somehow rely on gasoline(fluid) for lubrication.

Deprive them of lubrication(the gasoline in your tank) and it's just a matter of time before the pump goes bad .