Chosen Solution
I have a Maytag portable dishwasher (model # MDC4809 pab0) that is having a problem with the rinse cycle. It runs through the wash cycle fine, but when it starts the rinse cycle it continues to start and stop over and over again. Also, there is a strange black oily residue all over in the dishwasher.
A restricted drain could also cause this problem. Check your drain hose for a clog or restriction. Make sure that your sink drain and garbage disposal are draining properly. If you have an air gap installed in the drain line, make sure that it is not clogged. If you suspect that the dishwasher is not draining properly but find no drain system restrictions, then you could have problem with the drain check valve. Your front dishwasher door panel may have a sound absorbing material called black mastic. If this material deteriorates and leaks down into the tub, it can cause spots and deposits on dishes. To check for this problem, you would need to turn off the breaker and pull off the outer door panel of the dishwasher.
