Miele hydromatic w698?

So when the drain pump runs it makes a noise.
What part of the machine runs only at that time?
Tough one.
Maybe there's a motor driven something that only runs when the machine is emptying.
Could it be a failing motor bearing.
Maybe there's some kind of pump that only runs when the machine is emptying. A long shot but it could be something in the pump or a bearing in the pump or its motor.
Wild guesses of course.

Dfgyte
December 2021