My dishwasher appears to be running fine, but lately has made a audible noise during the wash cycle. I have noticed that when the wash stops and it is draining, the noise is gone. It doesn't happen on fill or when draining, just when actively washing. So i'm assuming it isn't associated with draining the machine.

I have attached a zipped mpeg4 audio of it. The previous owners of my house used to run it with a bad inlet valve, so it was always low on water. I fixed that when i bought the house and it has been fine since (fixed via another post on this blog)

This linked site is suggesting is could be the drain pump or the pump and motor assembly. I have also seen suggests that it could be the "grinder" piece or an "impeller".

Can someone give me an idea of how I can determine better what the issue is? Things I can look for or things I can rule out?

Thanks!