Dirty dishes coming out of the dishwasher would be unacceptable. First make sure the upper spray arm is not blocked and moves freely.
There are two things needed to clean the dishes well. There must be enough water and the water should be hot. The water level is normally just below the element. The water should be close to 135 degrees. You can check the water level and water temperature in the wash and final rinse cycle.
Check the upper spray arm for cracks or splits. Make sure that the upper rack is pushed all of the way in before starting a cycle so that the manifold will dock properly to provide spray to the upper arm. If there is any hard mineral buildup on the spray arms, soaking in some white vinegar can help clear it away.
Place a cup in each corner of the upper rack. Start a cycle and let it fill with water. After a minute or so of washing open the door and check the cups. Each should have an identical amount.
If there seems to be less water, then try moving the rack to a different level. The feed tub up the back wall has two docking ports, one for the top rack upper position and one for the top rack lower position. When one is in use the other should be blocked off.
The sump and pump housing should be cleaned and checked for debris or detergent buildup. Either can limit water pressure through the water tube and spray arms. Use the image below and this
to help check and clean the sump.This
can help check the drain and recirculating pump.
If parts replacement is needed, I do recommend having a technician make the repairs. This
Sears Home Services
link will help schedule. If further help is needed, please reply. Thank you for using Manage My Life.