The Impeller is an OEM part for Whirlpool brand dishwashers. Located within the dishwasher sump assembly, this plastic component utilizes rotating blades to circulate wash water throughout cycles. Causes of a bad impeller can include cracking or damage from minerals over time, chunks of food debris jamming the blades, or normal wear on plastic. Symptoms of a faulty impeller include:  Inadequate water circulation yielding poor cleaning  Food particles or utensils not fully rinsed Loud clicking or grinding noises mid-cycle Error codes relating to low water pressure Replacing the impeller restores optimum water flow for Whirlpool dishwashers. Proper circulation using the OEM replacement ensures all portions of dishes and cycles receive sufficient water volume. Compatibility also includes Maytag, Jenn-Air, Amana, Magic Chef, and other brands.Part Number 4386996A (AP6997612) replaces 4386996, 3369013.