Dishwasher: Making loud or strange noises

Some dishwasher noises are normal, like the hiss of water rushing through the water inlet fill valve, the hum of the pump motor or the slosh of water. But if your dishwasher is making strange sounds or is unusually loud, it's time to investigate.

A grinding noise could be caused by a popcorn kernel stuck in the chopper blade area of the dishwasher; a thumping noise could be the drain line vibrating against the cabinet. The wash pump, wash pump motor or drain pump all make noise when they’re broken. You may hear a loud buzzing noise from the wash pump or drain pump. The wash pump motor often squeals or whines when its bearing go bad.

The dishwasher also can make unusual noises if it's not fastened to the cabinet or floor. Learn how to refasten your dishwasher to the cabinet with our step-by-step video.

These repairs may help solve your Dishwasher problem:

Replace the dishwasher circulation pump and motor assembly

Sump and motor assembly

Several situations can require the replacing the circulation pump and motor assembly in a dishwasher. If the motor on the circulation pump fails, then the dishwasher pump won't run at all. Sometimes the motor runs but doesn't generate water pressure through the spray arms, because the damaged impeller or pump housing is damaged. The pump housing and/or the seals could also deteriorate or become damaged, causing the dishwasher to leak. Problems inside the pump and motor assembly can create abnormal noises in the dishwasher. In all these situations, the pump and motor usually must be replaced.

For manuals, repair guides, and specific part recommendations, enter your model number.

Replace the dishwasher drain pump

Drain pump

Replace the dishwasher drain pump if it's cracked or damaged, or if the drain pump doesn't pump out water. Before replacing, check the drain path (drain hose, sink drain and sump) to make sure it's not blocked. If the drain path is clear and water doesn't pump out, the drain pump has failed. Replace the drain pump if it won't run even though it's getting run voltage from the timer or control board.

For manuals, repair guides, and specific part recommendations, enter your model number.

Clear the dishwasher chopper blade area

Soil separator

A kernel of popcorn or a similar foreign object can drop into the chopper blade area of the dishwasher, causing a loud grinding noise when the pump runs. Remove the lower spray arm and the upper part of the dishwasher sump to access and clear debris from the chopper blade area. If the chopper blade is damaged, replace it.

For manuals, repair guides, and specific part recommendations, enter your model number.

Replace the dishwasher wash pump motor

Wash pump motor

The wash pump motor, which is mounted on the sump under the dishwasher, spins the wash pump impeller. The wash pump motor will make a loud noise when it is defective. You may also see cleaning problems due to decreased spray pressure. If the pump motor is bad, it will need to be replaced. The motor can usually be released and removed from the sump under the dishwasher tub. Consider replacing the water seals as well when the new wash pump motor is installed for optimal performance.

For manuals, repair guides, and specific part recommendations, enter your model number.