Probably not your problem but sometime past I posted:
"I had a 123 (300D Turbo) that had a very similiar problem. I went so far as to take the console apart, removed the radio, I was sure it had to be in the console area.
I am almost ashamed to say it was a golf ball rolling under the seat. My noise appeared taking left or right turns. I would hear nothing at first and then this rolling sound and then a light clunk. Drove us all crazy. I had been in the back seat feet area, down under looking under the front seats dozens of times.
I finally found the damn thing when I did a spring cleaning an pull the floor mats and the carpeting out. The golf ball was able to stay up agains the cross-member under the seats by the carpeting. Funny now! Not then!
Needless to say, check WAY under your seats. You might be surprised."
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)