Dishwasher is very noisy during operation; grinding, rattling, or loud humming sounds.

Safety first: Disconnect power before reaching into the sump or removing panels.

Steps:

• Check inside tub: Ensure spray arms are not hitting tall items. Rearrange dishes and run a short cycle to test.
• Inspect sump: Remove filters and look for glass, bones, or other debris in the sump that could contact the pump impeller.
• Tighten fittings: Check that the dishwasher is level and that mounting brackets to the cabinet are secure to reduce vibration.

When to call a technician: Persistent grinding or loud humming often indicates a failing circulation or drain pump that should be replaced by a professional.