A recurring debate surrounds a constant ticking/rattle heard in driving videos: some owners insist it is unique to W126 sedans and comes from inside the car, while others attribute it to the microphone amplifying road noise. One frequently cited fix pins it to the bottom of the door card rubbing a plastic piece on the door sill, cured with smooth tape.
The W126 cabin 'ticking' noise
Mercedes-Benz S-Class (W126) · ownership