I wish I could share a resolution but my issue is still ongoing. But I can provide an update where I am at. We setup an initial appointment with the KitchenAid recommended service provider. We did not have the dishwasher running when they came out, and the tech was not able to hear the noise while he was here. We were told there was nothing to diagnose, that we should make sure our dishes are not interfering with the spray arms. We told him we ran the dishwasher empty, tried multiple cycle options, and we're still hearing the noise. He still said he wasn't able to do anything. We emailed the video of the noise over to a senior technician at the service provider and they decided to order several parts: the main pump assembly, vent assembly, and gasket. When the new technician came out to replace these parts, he was able to pull fault codes, but didn't hear the noise in person and didn't believe the parts that were ordered would fix our problem. So he left and had a water inlet valve shipped to us. We finally received the part and the technician came out again. This time we ran the dishwasher ahead of time and paused mid cycle when it started making the noise. Of course when he resumed the cycle the dishwasher never made the noise. The technician didn't want to replace all of the parts like he previously planned, because he essentially wants us to be guinea pigs and troubleshoot the parts individually so he can let Whirlpool know of a resolution. So he insisted to only replace the water inlet valve; we immediately ran the dishwasher after he left and heard the noise on schedule so we called back and apparently need to go through Whirpool all over again because our case was "closed".
This has been such a nightmare. We thought we were investing in a quality KitchenAid product. We have been trying to get this fixed for months now; if I would have known how long this would take I would have exchanged at Lowe's. Something tells me this is going to be a problem with all the units. Sorry I don't have better news. I'll post again if we come to a resolution.