Thanks Dave, The problem here is the solenoid on top of the water valve is causing the noise and vibration, it's basically going to fail completely soon. You would need to replace this valve, to do this pull the unit out from the wall, Take the screws out along the rear lip and take the top off the machine, you should now hove access to the valve in order to replace it.
I have checked the part on several sites, no one has it in stock, I have included a link where you will have the best chance of getting the part faster.
To order your replacement part>>>>> CLICK HERE <<<<< To order your replacement part.
I would like to earn your highest rating Dave, If I provide you with a answer this just means with the symptoms you have supplied me I am letting you know from experience where the problem is, this does not mean however that we have finished, If you have any additional questions please reply.
If I have answered your questions to your satisfaction please feel free to come back at any time after rating me "Excellent service" for additional questions you may have at no further charge :)
Sometimes I will have to give bad news, Please try to find it in yourself to rate me for the service not the bad news.
If you would like to request me personally for future appliance questions click here HERE and bookmark this page.