Whiny grindy noise during operation

Over the last two weeks our dishwasher has become louder and louder with a whiny grindy noise that is more whiny and seems to be coming from the lower left corner of the dishwasher when you put an ear to it…
The motor was replaced by Maytag repair after two trips to our house for grindy noise under covered warranty. Now it is out of warranty and is making this annoying noise and we have checked for something in mechan ism…didn’t find anything and other than noise it still works..the only time the noise stops is during lull in it’s different functions.

Worry that I will be looking for a new dishwasher soon.

Here are your parts
Replacement parts for MAYTAG MDBTT79AWB | AppliancePartsPros.com

Here is a tech sheet, a manual and a couple bulletins on noisy motors.
http://www.servicematters.com/maytag_library/docs/16021814.pdf
http://www.servicematters.com/maytag_library/docs/16023223.pdf
http://www.servicematters.com/maytag_library/docs/TDD-0013-B.pdf
http://www.servicematters.com/maytag_library/docs/TDD-0015-B.pdf

The above should help you determine if the motor needs replacing.

http://www.applianceaid.com/maytag-dish-noise.html. I had kind of the same problem. Turned out to be this housing.