How to resolve a dishwasher making loud grinding noises?

 

Check for Foreign Objects in the Dishwasher

 

A common cause of a dishwasher making loud grinding noises is a foreign object caught in the dishwasher's pump, chopper assembly, or drain impeller area. Often, small hard items such as glass shards, fruit pits, bones, or utensils accidentally fall into the dishwasher and cause grinding friction against moving components.

• Turn off and unplug or disconnect power to the dishwasher before inspecting to ensure safety.
• Remove dish racks and visually inspect the bottom of your dishwasher for objects that may have fallen into the chamber.
• Check the dishwasher's drain basket and carefully remove any stuck debris.
• If your dishwasher has an easily accessible chopper blade or impeller, inspect the area closely and remove any foreign objects that may have gotten stuck there.

 

Inspect Your Dishwasher’s Chopper Blade or Food Grinder

 

Dishwashers often contain a chopper or grinder blade designed to pulverize food particles, preventing clogging. If the blade or grinder assembly is damaged, clogged, or partially broken, it will produce loud grinding noises during operation.

• Consult your dishwasher’s manual to locate the chopper blade assembly (usually beneath the bottom rack and spray arm).
• Carefully access the component and visually inspect it for damage or debris buildup that could cause the noise.
• If damage is found, the part may need replacement or professional assessment.

 

Examine Dishwasher Spray Arms for Damage or Blockages

 

Spray arms spin to distribute water evenly during the washing cycle. Sometimes, damage, blockage, or collision of these spray arms against dishes or other dishwasher parts can cause a loud grinding or knocking sound.

• Remove all dishes and pans, pull out the dishwasher racks, and manually spin the spray arm assembly to ensure smooth rotation.
• Check spray-arm holes for blockages; a toothpick or small brush can help clean clogged openings.
• Ensure the spray arms are securely attached and not loose. Tighten or reinstall spray arms if necessary.
• Replace damaged or cracked spray arms to eliminate grinding sounds during operation.

 

Review Dishwasher Pump and Motor Assembly

 

Grinding noises can originate from worn or failing dishwasher pump bearings or components within the circulation pump and motor assemblies. Over time, exposure to water and detergents can reduce their lubrication and cause wear, resulting in noisy operation.

• Carefully look beneath your dishwasher for leaking water or evidence that bearings or seals have deteriorated.
• If you have experience and feel comfortable, access the pump assembly to check for worn bearings, motor shaft play, or internal damage.
• It may be advisable to hire a professional technician to diagnose or replace the pump and motor assembly if problems persist.

 

Check Dishwasher Water Inlet Valve Noise

 

Although less common, grinding or buzzing sounds may occasionally emanate from the dishwasher’s water inlet valve. Debris buildup or damaged valves may result in abnormal noises.

• Shut off water supply and power, access the water inlet valve typically located beneath the dishwasher or behind the lower front panel.
• Inspect valve for cracks, debris deposits, corrosion, or obvious wear.
• If you suspect issues with the water inlet valve, replacement is usually necessary.

 

Schedule Regular Maintenance and Servicing

 

Routine dishwasher maintenance can help prevent grinding noises and other breakdowns. Periodic cleaning to remove scale buildup, debris, and mineral deposits can improve performance and reduce operational sounds. If these troubleshooting tips don't fix your dishwasher noise issue, a professional technician can help identify and address underlying problems.

Whether you live in St Louis or Nashville, plenty of experienced appliance repair specialists are available to provide reliable, professional evaluation and dishwasher repairs.

• Always follow manufacturer-recommended maintenance schedules and best practices.
• Regularly inspect and clean dishwasher interiors to avoid debris accumulation.
• Professional servicing helps maintain optimal dishwasher function and significantly extends appliance lifespan.