Noisy Whirlpool Dishwasher

My dishwasher is noisy - only during weash cycles. I have completely removed the pump and cleaned everything out. Still noisy. Impeller spins smoothly on motor.

  1. Does anyone know how to run the motor while disassembled so I can see if it is the motor is the culprit?

  2. How do you remove the impeller from the motor?

  3. Any other ideas on isolating the noise?

Many, many thanks!
Paul