msv It’s sounds as if the pump is touching a component inside the case, that’s a bit of a metal on metal sound. I would remove the case and look to see if it’s touching anything…or anything attached to the pump that’s solid is touching anything. If it’s not, run the pump and see if you get the same noise.. If the noise is absent, then it’s (or something attached to it) touching the case itself
The only other possibility if the pumps definitely touching nothing, is the solenoid is buzzing, this could be because of debris under the solenoid valve seat. If so, it will need to be taken apart for cleaning. You can try lifting the water inlet tube from the tank…if bussing sound remains the same, but the underlying pump sound changes, it could well be solenoid.