Consider that you may have water hammer in the supply pipes - as a valve closes a pressure wave is sent back and forth causing the pipes to vibrate - like water in a bath sloshing from one end to the other - an electronics engineer sees the same thing on high speed signal cables - terminators soak up the excess energy.
You might try slightly adjusting the water pressure at a nearby stop valve.
Listen carefully - is it the machine making the noise or the pipes leading to it?
Good luck...
Pitt the Younger, September 2014
