If you are talking about the main fuel pump under the car, rear driver side, they do hum, loud hum might mean it's loose under there, but if humming becomes a whine or screech it's days are numbered. Pretty straightforward swap out, you will spill some gas (pull fuse and let car die to lose pressure). FCP, Tasca all have these, check for best price, stick with the Bosch pump, not some cheap one that will fail quickly. Good luck.