GE dishwasher not cleaning dishes

[MerciMe]

Our dishwasher  is 5 years old (new construction) and it was cleaning fine except for frequent problems with the soap left in dispenser at the end of the cycle.  In the last 8 months we have had a problem with spots and a white film appear on our dishes, as well as tiny food particles, and if I left water sitting in a glass before washing, it would come out with a ring around the glass.  I use Cascade powder and Jet Dry rinse agent.  I have tried everything to remove the film from the glasses but only manual bleach bath does the job.  We use a brush and rinse off the dishes before loading so little food is on the dishes when they are loaded.  Today I pulled the lower arm off the washer and the platform below it.  I found a buildup of a black and white dry substance coating the plastic housing (not sure that is the correct terminology) and some that flaked off. (picture attached)  I have purchased a dishwasher cleaning agent that was highly recommended and used that as well as run a vinegar wash but no change.  Any ideas of what may be causing this problem?

Model PDW7880J01SS

[jumptrout51]

Please describe how your drain line is connected under the sink from the dishwasher all the way to the drain outlet.
Thank you.

[MerciMe]

From what I can tell the white flexible tubing is coming from the dishwasher directly to the disposal which then  flushes to the drain.

[jumptrout51]

Check the bottom spray arm for blockage in the water port holes.
Put a glass,right side up in the top rack and bottom rack. Then run the machine.
Does the top and bottom glass have water in them?
When you set to drain,pay attention to the disposal to see and hear if the drain water is pumping out OK.
The raised plastic piece in the rear floor of the machine can be removed,then put your fingers in the opening to feel for debris in the drain sump.
BE VERY CAREFUL. There could be broken glass in there.

[MerciMe]

Are you referring to the part that looks like an upside down basket?  I tried to get that off because it looks like a lot of this granular stuff has collected in it but I can't get it out from under the pipe.  It appears that the pipe has a tab release but I'm afraid I won't get it back on if I take that off.

[jumptrout51]

Yes that is what I am referring to.
And, Yes,it comes off.

[MerciMe]

You will have to explain how to remove that part as the pipe is holding it down and I can't seem to see how to do it.

I thoroughly cleaned the pipes and spray arm.  Removed a lot of debris.  Then I ran a load but no luck.  Same food bits about the size of sand and white film.  The plates also seem to have a "grit" on the backs of them when I run my hand over them. 

The soap dispenser does not completely dissolve the soap and this has been more frequent lately.  I am guessing the hatch does not open all the way.  I try to make sure nothing is blocking it and all the shelves are pushed in.  It did that today so I stopped it before the rinse cycle and restarted with a short wash.   

I did not check to see if the water was draining out the garbage disposal as you asked.  Will do that tomorrow.

[MerciMe]

I also put a glass facing up in both the upper and lower racks and both had a cup of water in them.  There were granules of soap in the bottom but I presume that is because in this position, it could not rinse out properly.

[JWWebster]

Jumpy if the knockout inside that disposal is not completely removed would that cause her symptoms?

[jumptrout51]

Yes JW,or any other blockage or slow drain issue with the disposal or plumbing.

[jumptrout51]

I believe this drain sump cover snaps in place. Squeeze the sides to remove it.
Are you on a well or municipal water supply?

[tgoods]

If it's the same dishwasher I'm thinking of, it's a very poor design.  The food chopper is on the back side of the inlet.  Get it apart, clear the buildup from the inlet and it will work fine until it plugs up again.

[MerciMe]

We are on NRD water which is city water in origin.  I don't know what NRD does to it if anything, but it seems a lot harder than when we lived in the city.  We are also on a septic and don't use the disposal except for bits and pieces.  So it couldn't be a backwash.

I have tried squeezing it but the problem is it has to lift and there is no room under the pipe.

[MerciMe]

JW, if the knockout wasn't removed all the way, wouldn't I have been seen problems before now (5 years after installation)?

[rmbraught]

If this is the design I'm thinking of, I don't really know how hard water would affect it over time (we don't see many in this area) *but*
if it's the design that uses a ball check (and a little arm actuated flap at the bottom of the sump to 'direct' the ball up/down) the ball check is what determines whether or not it goes into full drain or not; so my conjecture is that after deposits build up over time, the ball check valve wouldn't seat properly; I suppose it might reduce wash pressure too?
If it's the design I'm thinking of, the ball is right below the riser above the sump screen. I'd be looking for anything that would restrict or otherwise prevent the check ball from free motion or fully seating.