The problem is a bad pump seal. You can try to repair the old pump or replace the whole pump and motor assembly. The new pump and motor assembly comes with the new redesigned motor which is much more quite.
You can find more useful information in one of our previous threads: Hums But Won't Cycle; No Water Flow
- The pump seal and impeller kit Part number: WD19X10032
- The pump and motor assembly Part number: WD26X10013
Here are the breakdown diagrams and Replacement parts for General Electric GSD3210Z00AA Dishwasher | AppliancePartsPros.com