whirlpool W10431036A Dishwasher smells and doesn't fully clean

[fridge123fr]

Dishwasher about 12 years old.
I think it started with bad smell after washes (which came out perfectly clean though) and I learned to keep the bottom filter clean (I never really knew it was there and just assumed the dishwasher/food disposal took care of food bits).

Recently it was starting the cycle by filling the bottom with water as it should but then stopping. I had to press cancel/start button and that's all I could get the machine to do.

I checked the float sensor on the bottom seemed good.
The clear hose leading to the food disposal seems clean but does have some dark smudges within it but I don't think a slightly clogged exit hose is causing the problem.
I pulled the unit out to get familiar with the pump assembly since that's what researching lead to be a likely problem. But while I had the unit pulled out and ran it, it went through the complete cycle and seemed fixed by itself. I pushed it back and used it a few times no problem except that the bad smell after washes came back quite obviously. So I made sure filters were always clean but it would still smell and now it's not doing a great job at washing. I sometimes have to run it twice and set it for 'heavy, pots and pans', and now it just doesn't wash nearly as good as it should and still smells pretty much constantly.

[EthanRanft]

Assuming you put everything back together correctly and nothing is kinked underneath or behind the dishwasher. It’s possible that for some other reason it isn’t fully draining out and food is hanging around in the bottom, even in the sump where you can’t see. So I would say to check everything in the drain system again, pump, hoses, etc

[fridge123fr]

sorry the model # in title is wrong, it's

whirlpool WDT710PAYM2
s/n F21320874

 

But even if it's only collecting food scraps instead of sending them out the tube, it's still not washing very good.

[EthanRanft]

What I mean is if it’s only partially draining, then each time it’s leaving dirty water in the bottom

[David Jero]

After 12 years I am guessing the wash pump motor is starting to stop running during the cycle. Keep this in mind. All a dishwasher does is basically 3 things. Fill, wash and drain.  As long as you have at least 120 degree water.  Quality water and soap you should be good to go.  These wash pumps are known for stopping while being powered up by a rubber bushing being worn in the motor itself.  It's a magnetic style motor. When the bushing gets worn the rotor isn't aligning properly and it just sits there when it should be washing. An easy way to determine this is when it is washing you can here the motor stop and hum. Sometimes you can give it a love tap and it will start running again. 

I would replace the whole assembly because you get a new diverter motor and diverter seal along with a new wash motor. This will basically eliminate a possible bad diverter motor and or wash motor.  The diverter o-ring are known to leak on these and replacing the sump is the only way to solve it. So you kill 2-3 problems at once. 

WPW10482482

As long as the spray arms are clean.  You have enough water going in. The water is hot. The water quality is decent. You are using quality name brand soap.  This is all you can do. 
 

[EthanRanft]

Only other thing is the filters or screens in dishwashers can get clogged and cause loss of pressure. Probably not the problem here though

[fridge123fr]

I think it might have only been a clog in the P trap and the line from the secondary sink. The dishwasher runs into the food disposal under the main sink and there's a side sink that connects to just above the P trap, well the horizontal pvc running from the secondary sink was a tad unlevel in the wrong way. I noticed the side sink was draining slow so I thought it was the P trap. I took all the PVC apart. The vertical pvc from the side sink was almost clogged shut, the P trap was clean. I'm hoping it was simply that when the chunks of food fill the P trap, it enters the horizontal PVC from the side sink and then struggles to push everything up and out the P trap. Thus was getting cloudy dirty water sometimes and the smell was also coming from the side sink (although much more noticeably when the dishwasher was opened, which seems sort of contrary to the clogged PVC from the side sink being the cause which should smell as bad above the sink as the dishwasher smelled.

Anyway, it's being working fine though mostly for the past few weeks from starting this thread, but then just now cleaned major clogging in the pvc so hopefully that's all it was.