This thread is a bit dated, but it helped me diagnose and fix a similar problem with my Kenmore Elite model 665.77979K703 (made by Whirlpool), purchased in Oct 2010. At the end of the cycle there would be white coloured water in the appliance and running a "empty/drain" step would cause turbulence in the sump, but the water would only drain very slowly, and the two minute max for the drain step would be reached before all the water was drained.
Before pulling out the dishwasher I tested the amount of water being drained by detaching the drain hose at the sink end and briefly running the "empty/drain" step. A trickle of water came out, indicating an obstruction in the drain line or a problem with the DW itself.
Having pulled the dishwasher and checked the drain hoses for obstructions (none found) I then removed the little drain pump (very simple, just twist and hold in a safety prong at the rear). I found a thin strip of what was once plastic wrap right where the impeller was. Removed it, then re-assembled the machine and now it runs as it should.