If it is just making a horrible noise when it is pumping water and draining you have a simple fix. Pull out the bottom rack. With a Philips head screw driver remove the bottom screen panel and the spray arm. You will see small plastic teeth around the circular drain. Look closely and you will find a small partial that has fallen into that area and being continually hit as the unit pumps. Put all back as it was and do a load. One tine from a plastic fork can make a dishwasher seem that it is ready to explode.