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Fix a dishwasher that makes noise

We'll identify the noise by location—pump, spray arm, filter—then fix it or tell you when to call a pro.

Troubleshooting · Home appliances
15–45 min
What you'll need
  • Screwdriver set (Phillips and flathead)
  • Toothpick or small brush (for spray arm holes)
  • Replacement pump (if tests show a fault)
Step 1 of 7

Quick triage — pick your path

Quick triage — pick your path

Choose the option that matches what you see. You can jump straight to that section.

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Steps

Goal: Confirm the noise is unusual, identify where it comes from, then fix the spray arm, filter, drain hose, or pump—or know when to call a pro.

  • Run a wash cycle and listen. Normal: soft hum, water spray, drain gurgle. Unusual: loud grinding, buzzing, rattling, or thumping.
  • Symptom confirmed: Noise is unusual—proceed to Identify location.
  • No problem: Soft hum and spray sounds—normal operation. No action needed.

Identify where the noise is loudest

Goal: Narrow the cause by location.

Spray arm

Goal: Stop rattling or knocking from the spray arm.

  • Open the dishwasher and inspect the spray arm. Confirm it is seated on its hub and spins freely.
  • Check that dishes are not blocking the arm from rotating. Rearrange loads so the arm has clearance.
  • Clear food or debris from the spray holes with a toothpick or rinse under water.
  • Good: Arm spins freely during a cycle. Rattling stops.
  • Bad: Still rattling after clearing—check the filter and pump.

Pump and filter

Goal: Fix grinding or buzzing from the bottom—filter or pump.

  • Clear the filter. Twist or lift it out per your model. Rinse and remove debris. Reinstall firmly.
  • Look for loose objects in the sump—silverware, glass, or food. Remove any you find.
  • If grinding continues, unplug the dishwasher and access the drain pump per your model. Check your owner’s manual or search “[brand] [model] dishwasher service manual” for disassembly steps.
  • Remove the pump inlet and check for debris. Clear any blockage.
  • Good: Filter clear, pump inlet clear—noise stops.
  • Bad: No debris and pump still grinds—pump failure. Replace or call a pro.

Drain hose

Goal: Stop thumping or rattling from the drain hose.

  • Pull the dishwasher out or access under the sink. Inspect the drain hose where it runs to the drain or garbage disposal.
  • If the hose touches the cabinet, floor, or other parts, it can thump during the drain cycle.
  • Secure the hose with clips or reposition it so it does not contact surfaces.
  • Good: Hose free of contact. Thumping stops.
  • Bad: Still thumping—check that the hose has a proper high loop; call a pro if the noise continues.

When to get help

Call an appliance technician if:

  • The pump grinds with no debris (pump or motor failure).
  • You have cleared the filter and spray arm and the noise continues.
  • You are not comfortable accessing the pump or electrical parts.
  • The dishwasher shows error codes.

Do not attempt to repair a sealed pump or motor yourself.

Verification

  • The dishwasher makes normal sounds (soft hum, water spray) or the unusual noise is resolved.
  • Spray arm spins freely; no dishes blocking rotation.
  • Filter is clear and seated correctly.
  • Drain hose does not contact cabinet or floor.
  • No grinding or buzzing from the pump area.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Confirm symptom Verify the noise is unusual—not normal hum or spray sounds.
  2. Identify location Listen at bottom, spray arm, and sides to narrow the cause.
  3. Spray arm and filter Clear spray arm obstructions; clean and reseat the filter.
  4. Drain hose and pump Check hose contact; inspect pump for debris.
  5. Call a pro Pump grinds with no debris, or repeated noise—call an appliance technician.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Where the noise is loudest (bottom, spray arm, sides)
  • Whether the filter was clogged
  • Whether the spray arm spins freely
  • Debris in pump or sump
  • Steps already tried

Is the noise unusual?

Normal: soft hum, water spray, drain gurgle. Unusual: loud grinding, buzzing, rattling, or thumping.

Run a wash cycle and listen. Symptom confirmed: loud grinding, buzzing, rattling, or thumping—proceed to identify location. No problem: soft hum and spray sounds—normal operation.

Symptom confirmed No problem

You can change your answer later.

No action needed

The dishwasher makes normal sounds. No further action required.

Done

Is the noise loudest at the bottom or spray arm area?

Bottom points to pump or filter. Spray arm points to obstruction or loose arm. Sides point to drain hose.

Listen at the bottom, spray arm, and sides. Bottom or spray arm: check spray arm, filter, then pump. Sides or back: drain hose contact—secure or reposition.

Bottom or spray arm Sides or back

You can change your answer later.

Drain hose contact

Check the drain hose where it runs to the drain. If it touches the cabinet or floor, secure it with clips or reposition. Thumping and rattling often stop when the hose is free of contact.

Done

Spray arm or pump?

Spray arm: rattling, knocking. Pump: grinding, buzzing.

Spray arm: Check that dishes are not blocking rotation; clear holes; confirm arm is seated. Pump: Clear the filter first. If filter is clear and grinding continues, check the drain pump for debris. No debris and still grinding—pump failure; call a pro.

Spray arm Pump

You can change your answer later.

Spray arm clear and seated?

Clear debris from spray arm holes. Confirm arm is seated on hub. Check dishes are not blocking rotation. Good: arm spins freely—noise should stop. Bad: still rattling—check filter and pump.

Done

Filter clear and pump free of debris?

Clear the filter. Inspect the sump and pump inlet for debris. Debris found: remove it, reassemble, test. No debris, still grinding: drain pump or circulation pump has failed—replace or call a pro.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a dishwasher grind or buzz?
Common causes: debris in the drain or circulation pump, a clogged filter straining the pump, a loose or obstructed spray arm, or the drain hose hitting the cabinet. Identify the location first.
Is it normal for a dishwasher to hum?
Yes. The pump makes a soft hum during fill and wash. Unusual noise is loud grinding, buzzing, rattling, or thumping. If the hum is steady and not loud, no action is needed.
When should I call a technician for dishwasher noise?
Call a pro if the pump grinds with no debris (pump failure), you have cleared the filter and spray arm and the noise continues, or you are not comfortable accessing the pump or electrical parts.

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