I have had this problem with a 190E. It would do it itermittently for a week (sort of a clicking noise from stop until abouy 25mph). I could not duplicate the noise on jacks nor could I find anything wrong with the car. It went away and came back about a year later for a week. It has not return and it has been about a year and a half.
Let us know what you find out, because others have had the exact same problem. Check out prior posts on this subject.
1990 190E 2.6
1996 Grand Voyager 3.3
1985 Mustang GT 5.0 5 SPD
1982 Suzuki GS 750T