Noise on fill or when cycle is ongoing before wash cycle/modeas far as i can tell. Its a Bosch SMS50T02GB/40. I have already removed and checked the drain impeller pump and made sure no obstructions in the main body of the unit. During the rest of the cycle it is silent running - is there a solenoid or valve that changes direction or something that could be making the noise as it reverses flow or something like that? UPDATE: I found a related post on here that pointed me in the direction of the spray arms. I removed the upper spray arm - noise goes away. Put it in again - noise comes back. My only question is this: by removing the spray arm, i reduce the incoming pressure...the noise is loud enough to be more than plastic and there are no moving parts other than the spinning arm. Could the noise be related to a pump that is straining to get the water up to pressure when the upper arm is in place? If so - which pump would this be please? Thanks for your views

Washing Machines - Bosch