Diagnosis
A foreign object—like a broken piece of glass, bone, or utensil—is caught in the drain pump impeller.
How to Fix It
You need to access and clear the drain pump.
- Disconnect power. Remove the lower dish rack and the filter assembly (turn the cylinder filter counter-clockwise to lift out).
- Look down into the sump area at the bottom and use a flashlight and needle-nose pliers to remove any visible debris.
- To check the pump, you'll need to remove the toe kick panel and possibly disconnect the drain hose from the pump to feel for blockages.
If That Didn't Work
If the impeller spins freely but the noise persists, the drain pump motor itself is failing and needs replacement. It's a known wear part.
Heads Up
Always scrape plates thoroughly. The filter is not a garbage disposal. A persistent grinding noise will destroy the pump quickly—don't ignore it.