LG LDT5678SS Dishwasher Loud Whirring: Check the Cause Before Replacing It

Use only checks that match the exact appliance or system and its official guide.

1. Check 1

   Pause or cancel the cycle and note whether the loud whirring occurs during fill, washing, draining or drying. Record whether it is a steady whir, an air-suction growl, a rattle, a squeal or a grind, and whether cleaning performance, draining or leakage changed at the same time.

   Expected result: The sound is tied to water entry, a filter or drain event, a spray/wash period, or a high-pitched squeal or grind that persists across the cycle.

   Next step: Use the matching external check below. Stop running the dishwasher and arrange service for grinding, a burning smell, leaking, poor draining or a rapidly worsening sound.

   Why this matters

   Why: LG maps those sound patterns to different possible sources: water flow, filter/load, drain obstruction or a possible pump problem. Timing narrows the next check but does not prove a motor failure.

2. Check 2

   With the cycle stopped and the interior safe to access, check that no utensil or dish projects into the spray path, strikes another item, or touches a rack or spray arm. Reload only loose items and do not reach into a moving dishwasher.

   Expected result: A dish or utensil is protruding or rattling, or the load is secure while the noise continues.

   Next step: Correct the accessible load and run only a supervised short check if there is no leak, odor or harsh mechanical noise. If the sound remains, stop testing and inspect the filter and drain path.

   Why this matters

   Why: LG says improperly loaded dishes can rattle and utensils can hit spray nozzles or other dishes. A secure load makes that explanation less likely but does not identify the wash motor or pump.

3. Check 3

   After the dishwasher is stopped, inspect the accessible filter as described in the LDT5678SS manual. Check that it is seated and not visibly clogged with food or foreign material; do not remove the pump cover, insert tools into the pump or run the unit with the filter loose.

   Expected result: The filter is loose or clogged, or it is clean and firmly seated while a growl or whir remains.

   Next step: Clean and reseat the filter using the exact manual procedure. If noise, standing water or slow draining remains, keep the dishwasher off and arrange service rather than reaching into the pump.

   Why this matters

   Why: LG identifies a loose or clogged filter as a source of rattling and says food waste or foreign objects can contribute to air-suction or drain noise. A clean, seated filter does not rule in a failed pump or motor.

4. Check 4

   If the noise occurs while water enters, observe the visible supply hose and shutoff area for a kink or an obvious restriction without disconnecting the line. If the unit is making an air-suction or growling sound, note whether the sink drains slowly and whether water remains in the tub after the cycle.

   Expected result: The whistling or growling is limited to fill/drain events, the visible supply path is kinked, the sink drains slowly, or the noise continues during washing with normal drainage.

   Next step: Follow the exact model guidance for an accessible hose or filter condition. Do not loosen plumbing, use a chemical cleaner in the dishwasher, or dismantle the drain or pump; call service if the path is restricted or the sound persists.

   Why this matters

   Why: LG says high water volume can make inlet whistling louder, and a clogged drain path or excess food waste can contribute to growling. A wash-period whir with normal water movement needs a different diagnosis and cannot be assigned to the motor from timing alone.

5. Check 5

   Record the LDT5678SS model and serial numbers, the approximate purchase or delivery date, the sound recording or description, and the result of the load and filter checks. Ask LG to assess the motor symptom and confirm the exact warranty terms before authorizing a motor repair or replacing the dishwasher.

   Expected result: LG confirms a model- and date-eligible direct-drive motor claim, or the coverage does not apply or the cause has not been diagnosed.

   Next step: Use the confirmed coverage and technician diagnosis to compare repair and replacement decisions. If the noise is unexplained or hazardous, leave the dishwasher off and use LG service rather than buying a guessed pump or motor.

   Why this matters

   Why: The LDT5678SS product page lists Direct Drive Motor coverage as 10 years under extended warranty information, but separately lists labor and parts terms and directs owners to the detailed warranty document. Coverage does not itself prove that the motor caused the noise.