I can help. I learned from my daughter leaving wet clothes in the washer for a few days and I would find them smelling sour. I found that if you put a cup to a cup and half of white vinegar in a full load let it agitate for a few seconds then let it sit for about a 1/2 hour to an hour in the vinegar water then let the cycle run. This usually will do the trick. Depends on how bad the smell is you may have to do it again. You can also add soap to the water.
Good luck!