Whenever I turn the dishwasher on, the lines make a huge rattling noise as the dishwasher fills. The dishes on the top rack never get cleaned, but the bottom works great. I've just been washing all my dishes on the bottom rack and not using the top at all. When I listen to it run, it just sounds like water is trickling around. I've poured water into the bottom of the dishwasher near the beginning of the cycle and this seems to help sometimes. Is there anything I can do short of calling a repairman?:confused: