Short answer: A grinding sound during a cycle almost always means a hard object — a fruit pit, bone fragment, piece of broken glass, or a stray bit of hardware — is caught in the chopper blade or pump area that breaks down food waste before draining. It's usually accessible from the filter area for a quick check, but the object itself can be sharp.
Because a chopper blade or pump jam is by far the most common cause, and it's often reachable from the same filter access point used for routine cleaning, this is worth a careful look before assuming a bigger mechanical problem.
| What you notice | Most likely cause |
|---|---|
| Sound is loudest during drain | Object caught in the chopper blade |
| You recall a bone, pit, or chipped dish recently | Hard fragment lodged in the sump |
| Sound is constant, not tied to a specific stage | Possible worn pump or motor bearing |
| Draining also seems slower than usual | Debris also partially blocking flow |
1. Hard object caught in the chopper blade
Many dishwashers have a small chopper or grinder that breaks down food waste before it drains — bones, fruit pits, and similarly hard items are common causes of a jam here.
2. Broken glass or ceramic fragment
A chipped or broken glass or dish can leave sharp fragments that reach the chopper or pump area and cause a grinding sound as they're struck repeatedly.
3. Foreign hardware or utensil fragment
A small piece of cutlery, a screw, or other hardware that shouldn't be in the dishwasher at all can cause the same symptom.
4. Worn pump or motor bearing
Less common than a jam, but a worn bearing in the wash or drain pump motor can also produce a grinding sound, independent of any trapped object.
Unplug the machine first
Always disconnect power before reaching into the filter or sump area.
Remove the filter and inspect the sump
With the filter out, carefully look into the accessible area beneath it for any visible hard object, using tongs or gloves if you suspect glass.
Remove any object found
Carefully extract anything you find, checking that it wasn't part of a larger dish or utensil that might also need repair or replacement.
Test with a short cycle
Restore power and run a short cycle, listening for whether the grinding has stopped.
Safety warning
Always unplug the dishwasher before reaching into the filter or sump area, and be cautious of sharp fragments if you suspect broken glass or ceramic. Do not attempt to access the chopper blade, pump, or motor assembly beyond the filter area — that level of disassembly should be handled by a qualified technician.Fruit pits, bone fragments, and pieces of broken glass or ceramic are the most common causes — anything hard enough to resist the chopper blade rather than breaking down normally.
With the machine unplugged, checking the accessible sump area beneath the filter is generally fine — just be cautious of sharp edges if you suspect broken glass, and use a tool rather than bare fingers if unsure.
Grinding is a mechanical sound from something being crushed or struck repeatedly, usually tied to a trapped object. Buzzing tends to be more of an electrical or vibration-related hum — see our dedicated buzzing noise guide if that description fits better.
Home Solutions Editorial Team
Reviewed against manufacturer documentation. Updated August 15, 2026. How we write guides
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