The fuel pump in my 90 300SE hums fairly loud. I am wondering if it could be an accumulator problem or the pump itself

PaulG

If the sound is changing, the pump (or two) may be heading south. Or it could just be a rubber mount.

Mine has been doing this for the past 5 yrs. Pierburg pump. Filter changed annually irregardless of mileage.

Thanks guys. Filter is changed religously and the mounts are all there. Guess I'll put a pump on the shelf.as a back up.