Noisy fuel pump

Mon Sep 14, 2015 10:16 pm

I fitted a new aftermarket in tank fuel pump to my 1989 325i and the car has also had new fuel lines & filter. The new pump is very noisy, sort of buzzing sound, but the car drives well. Are aftermarket pumps more noisy than the Bosch originals? (I couldn't hear the old one). Could the new pump be faulty? Does a noisy pump always mean it is about to fail? Any help would be appreciated.

Mon Sep 14, 2015 10:21 pm

OE Bosch pump goes noisy when its copper commutator, that the carbon brushes run against, wears through. Any pump will be noisy if it is touching the bottom of the tank.

Mon Sep 14, 2015 10:54 pm

Thanks for your reply. The in tank mesh filter when fitted to the aftermarket pump, did seem to sit on or near to the bottom of the tank. The new pump didn't have a filter and they were not available, so I adapted the original filter off the Bosch one. Could this be the problem? What could I do? Remove the mesh filter altogether?

Mon Sep 14, 2015 11:42 pm

Certainly wouldn't advise removing the inlet filter on a permanent basis, but you could try it temporarily without it fitted, and see if that quietens the pump.