Dishwasher - Rhythmic Knocking Noise

A rhythmic knocking sound is most likely caused by the spray arm hitting something inside the dishwasher as the spray arm rotates. To solve the problem, rearrange dishware inside the dishwasher to provide clearance for the spray arms. The spray arms must be free to rotate for good wash performance.

 

You can check your dishwasher's the Owner's Manual for loading suggestions for your model.