Dishwasher Making Noise

Why Your Dishwasher Is Making Noise

If your dishwasher is making noise, in most cases it comes from debris in the filter or pump, a spray arm hitting an obstruction, or the drain pump working harder than normal. Start by checking the filter and the spray arms — most cases come from something the machine is striking or grinding against, not a failing part.

A dishwasher that sounds different than usual is usually reacting to a specific issue. Most new or worsening noises have a clear cause — and many can be fixed without professional help. Matching the sound to the part of the cycle is usually enough to narrow it down.

When Dishwasher Noise Is Normal

Dishwashers are not silent appliances. These sounds are typical and do not indicate a fault:

• A low hum or whooshing sound during the wash — water circulating through the pump and spray arms
• A louder rushing noise at the start or end of a cycle — water filling or draining
• A brief knocking or thumping at the very start — the door latch engaging or the wash arm beginning to spin
• Occasional clicking during cycle transitions — the timer or control switching phases

If the sound is new, louder than before, or happens at an unusual point in the cycle, investigate further.

Most Common Causes

1. Debris in the Filter or Pump (Grinding or Rattling)

This is the #1 cause of dishwasher noise. Small food particles, broken glass, or hard debris that bypass the filter can get into the pump and create a grinding or rattling sound during the wash cycle.

Signs: a gritty or grinding noise during washing, consistent throughout most of the cycle, sometimes louder at the start when pump speed is highest. The filter may also look heavily loaded or discolored. In many cases, cleaning the filter resolves the noise immediately.

2. Spray Arm Hitting an Obstruction (Clicking or Knocking)

The spray arms rotate during the wash cycle. If a tall item — a pot handle, utensil, or oversized container — blocks the arm's path, it produces a rhythmic clicking or knocking sound as the arm hits it on each rotation.

Signs: a repeating click or knock tied to the spray arm rotation speed, often starts right as the wash begins and stops if you rearrange the load.

3. Drain Pump Noise (Humming or Grinding During Drain)

The drain pump activates at the end of the cycle to push water out. A worn bearing, debris caught in the impeller, or a pump starting to fail can produce a loud humming, grinding, or buzzing sound specifically during drain.

Signs: the noise happens only during drain — usually the last few minutes of the cycle — not during washing. If water is also not clearing fully, see our dishwasher not draining guide for drainage-specific diagnosis.

4. Circulation Pump Wear (Steady Hum or Low Growl)

The circulation pump moves water through the spray arms for the full wash cycle. As bearings wear, it can develop a persistent low hum or growl that gradually gets louder over weeks.

Signs: a steady background noise present throughout washing rather than just at drain, with no obvious debris or obstruction as the cause. The machine still cleans normally in early stages of wear. If the noise becomes louder over multiple cycles, the bearing is wearing out rather than just obstructed and will need replacement.

5. Loose Items or Dishes Rattling

Improperly placed items can vibrate against each other or against the rack wires during the cycle. This is one of the most overlooked causes and one of the easiest to fix.

Signs: an irregular rattling or chattering sound, inconsistent from cycle to cycle, often tied to a specific item or how the rack is loaded.

6. Water Inlet Valve Buzz (at Fill)

The water inlet valve opens at the start of the cycle to fill the tub. A valve that is partially clogged or starting to fail can create a loud buzzing or vibrating sound during the fill phase only.

Signs: the noise happens only at the very beginning of the cycle while water is entering, then stops once filling is complete.

Troubleshooting Steps

1. Identify when in the cycle the noise happens

This is the most useful way to narrow the cause quickly. Listen carefully and note when in the cycle the noise occurs:

• Noise only during fill (start of cycle) → inlet valve
• Noise only during drain (end of cycle) → drain pump
• Noise throughout washing → spray arms, filter area, or circulation pump

2. Run an empty cycle

Remove all dishes and run a short cycle. If the noise disappears, a loose dish, utensil, or improperly placed item was the cause. If the noise continues with an empty tub, the problem is mechanical or related to debris in the pump.

3. Clean the filter

Pull the lower rack out and remove the filter assembly at the bottom of the tub. Rinse it under warm water and use a soft brush to clear any food buildup or debris. A clogged or debris-carrying filter is the most common fixable source of grinding noise.

4. Check the spray arms

Spin each spray arm by hand to confirm it rotates freely. Look for any food particles or hard debris lodged in the spray holes. Reload the dishwasher carefully and make sure no handles, lids, or tall items overhang into the spray arm path.

5. Listen for the drain phase specifically

Start a cycle and stay near the machine toward the end. If the loudest noise happens during the last few minutes when the pump is draining, the drain pump is the likely source. A buzzing drain pump that still clears water may have debris in the impeller — a pump that hums without draining points to a more significant failure.

6. Check that the machine is sitting level

A dishwasher that rocks slightly can amplify normal pump and water vibration into noticeable rattling. Press gently on each corner to check for movement. Adjust the leveling feet at the base if needed.

7. Know when the issue is becoming serious

A grinding noise that gets progressively louder over multiple cycles, a drain pump that hums without clearing water, or a circulation pump growl accompanied by worse cleaning results all indicate the problem is advancing. At that point, the pump or motor needs internal inspection — not something that can be resolved with cleaning or loading adjustments.