Your dishwasher normally makes a certain amount of noise. Grinding and grating sounds are just the dishwasher breaking up food particles. You may hear a clunking noise, especially near the beginning the cycle. Swishing noises are often from water moving around your dishwasher. Buzzing and clicking sounds are also common. If you open the door, you may hear a snapping sound, which is also normal.
If you hear a rattling inside your Whirlpool dishwasher, stop the dishwasher and rearrange your dishes. This noise is usually caused by plates hitting against each other, which causes chipping. If you hear a knocking noise, the spray arm is hitting against dishes as it moves around the dishwasher. Move any items blocking the arm. If you do not, your dishes won’t clean properly since water can’t move freely around the tub.
The pump may make a rattling or squealing sound when it’s new. Pour 1 qt. of water on the bottom of the tub to lubricate the pump seals. If you hear a grinding sound within the pump, food may be clogged inside. Stop your Whirlpool dishwasher, and disconnect it from the power supply. Take out the spray arms, bottom rack and spray arm support to access the pump. Clean the pump with a toothpick to remove any objects caught in it. Examine the inside of the pump, and see if the impeller is broken. Replace the whole pump if the impeller is broken, since it’s difficult to fix. The heater fan may squeal if it’s rusted or if the fan blade is loose. Change out the fan motor if rusted, or tighten the fan blade.
The motor is located inside the main access panel of the dishwasher. The motor has a plastic disk connected to it. If this component breaks, it can rattle around the motor shaft. Replace the motor, since you usually can’t fix the disc. Check the bearings, and see if they are extremely worn or wet. Get new bearings if old. Replace the main tub seal on the dishwasher if water is dripping on the bearings. You must get a new water inlet valve if it’s creating a thumping noise.