The 10KHz noise you here is from the motor drive circuit that feeds the motor on the right side close to the front. I placed a near field probe all around the DW and determined that there are significant emissions coming from this area. What does this mean? It means that the circuit was not designed properly. Experience leads me to believe that it may not cause physical damage but it can be corrected and Bosch needs to do so. I prepared a report for them. Rest assured this is not related to a bearing or the actual movement of a mechanical device, like a motor. It is caused by the circuit that makes the motor move.
SOURCE: Dishwasher Making Loud High Pitched Noise.
A loud high pitch whine while running the dishwasher means that there is something caught in the chopper assembly. To get to the chopper assembly you need to take the racks out and take the pump apart from the inside of the dishwasher. The chopper assembly looks like a metal grate with holes in it. And it might not even be stuck in the grate but somewhere in the pump area due to the water being pumped out, so the best idea is to take the whole thing apart and clean everywhere. However I do not recommend doing this unless you are completely certain you will remember where the screws and gaskets go, otherwise you risk damaging your pump or house from a leak or improper installation. You have been warned.
SOURCE: Dishwasher Making Loud High Pitched Noise.
Problem is with the main pump motor bearing. Water leaking from the face seal enters the front bearing. After some time, the bearing wears out bringing on the loud noise. The motor is easy to remove but the bearing requires some time to remove. I did not have access to a press so I ground off the bearing an replaced it with a shielded 8mmx22mm type. Grainger p/n 1L001. The part is only $9 compared to over $200 for a replacement motor. It takes some time and disassembly of the dishwasher can be difficult but take your time and be ginger with the parts. The root of the problem seems to be the impeller. It screws onto the motor shaft and seems to work loose after time. Since its tightness compresses the face seal, when it loosens water can seep. No way to lock it in place after tightening. Weak design point.
SOURCE: Dishwasher Making Loud High Pitched Noise.
How deep do you want to get into this?It sounds like the wash pump motor bearings that are worn.You can pull the unit out flip it over and wd40 the bearings in the motor or you can replace the bearings.Try to lube them first.
SOURCE: Bosch dishwasher whining
if you listen to the appliance and the noise is louder on the rhs and low down this is probably the main wash motor they sometimes do whine if you can live with the noise leave it alone if not you basically have to take the whole applianmce apart for access to the motor costly repair would take a trained pro about 90 mins to replace the motor
if the noise is coming from the front of the appliance more to the lhs and is intermittant ie when it first starts up and then about half way through its likely to be the drain pump relitively easy to replace and you dont have to take the appliance to bits just go at from the front
good luck
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I am on my second Bosch Ascenta from Lowes. Same very high pitched noise but not in the rinse cycle. These units are both right out of the box and as soon as you start a cycle ie test for leaks from installation the noise starts. Seems to be more of an electronic noise rather than a bearing failure or impeller debris noise. These 3 solutions don't seem to apply since I haven't run any dishes through them yet!
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