Dishwasher: Making loud or strange noises

Some dishwasher noises are normal, like the hiss of water rushing through the water inlet fill valve, or 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 thumping noise could be the drain line vibrating against the cabinet; a grinding noise could be caused by a popcorn kernel being stuck in the chopper blade area of the dishwasher.

The dishwasher can make unusual noises if it's not fastened to the cabinet or floor. View the following videos to see how to anchor the dishwasher inside the cabinet.

Troubleshooting Videos:

These repairs may help solve your Dishwasher problem:

Replace the dishwasher pump and motor assembly

Sump and motor assembly

Several situations can require the replacing the 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.

Replace the dishwasher water inlet valve

Water inlet valve

The water inlet valve, also called a solenoid fill valve, controls the flow of water into the dishwasher by opening and closing. If the water inlet valve doesn't open at all, water can't flow into the dishwasher. If it opens partially, the dishwasher won’t fill adequately, and the water level will be low—a noisy pump is one indication that the water level is low. Conversely, if the water inlet valve won’t close, water fills the dishwasher tub even when the dishwasher is off. If the water inlet valve doesn't open or close correctly, repair or replace it.

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

Replace the diverter motor

Diverter motor

The diverter motor moves the diverter disc into position so the disc can direct water through the upper spray arms. The dishwasher stops and signals an error code when the diverter motor fails (check out our dishwasher error codes for many brands). Replace the diverter motor if the control signals an error code indicating the diverter motor failed. To prevent damage to a newly installed dishwasher diverter motor, also replace the diverter motor seal (part WPW10195677) if water leaks through the seal. The seal is the gasket around the diverter motor shaft where it meets the bottom of the sump. A leak can damage the diverter motor, as well as counters and flooring near the dishwasher.

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.

Clean the dishwasher circulation pump

Sump and motor assembly

A foreign object such as an unpopped popcorn kernel or a shard of glass sometimes migrates into the circulation pump where it causes a grinding noise and interfere with water movement through the pump and sump area. In that situation, you will need to dismantle and clean the circulation pump. The foreign object and/or any debris will need to be removed, and the pump will then need be reassembled.

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.

Repair the dishwasher upper pump assembly

Upper pump assembly

Some dishwashers have a portion of the pump assembly that can be accessed and repaired from inside the dishwasher tub (from the top of the pump assembly). A clog, a foreign object, a failed seal, a bad check valve or damage to the upper pump assembly may require a repair. If there is a clog or foreign object in the assembly, the dishwasher water won't drain. Remove the lower spray arm and the top of the sump and then inspect and repair the pump components.

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

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