Plastic items and top-rack dishes are not getting clean; lower rack items are cleaner.

Safety first: Turn off power before removing spray arms if necessary.

• Clean upper spray arm: Remove the upper spray arm and clear all jets with a toothpick. Rinse thoroughly.
• Check feed tube: Inspect the vertical feed tube and manifold that supplies the upper arm. Ensure it is not cracked or disconnected.
• Rack engagement: Make sure the upper rack is properly seated so the spray arm hub engages the water supply at the back of the tub.
• Assess pump performance: If upper cleaning remains poor, the circulation pump may be weak and require replacement.