Kitchen Aid dishwasher making a loud grinding noise?

Most dishwashers have a recirculating water pump. This wash pump consist of a wash motor, propeller, chopper blade and screens. When these parts are working properly they circulate the water  up and through your spray arms upper, middle and lower.
Generally when the wash motor start going bad there will be a grinding noise that over time will get  louder. Keep in mind that items like toothpicks, plastic, popcorn seeds, and broken glass are all items that can and will effect the chopper blade and motor.
The chopper blade is connected directly to the wash
motor and is designed to help with small soft  food particles. It was never designed to be a garbage disposal chewing up anything that comes its way. I have found a good number of items in the bottom of the sump area, fish tank rocks, false teeth, rings, tooth picks just to name a few. Keep these items out and
your chances of needing appliance repair go down up to
90%.
Before making the call for appliance repair there are
a few simple items you can check. First thing is visually inspect the holes in your spray arms. If the spray arms are restricted the water will not be able to properly wash your dishes. The last item would be to remove the screens in the bottom of the dishwasher and inspect for restrictions there. If these areas of your dishwasher are clear and free of debris its time to call for service.