A new sound appeared today in my 05 TL 6M. A momentary rattle in the moonroof in the tilt position, which disappeared by closing the roof - thereafter, the tilt position rattle was gone.

However - a clunking sound emerged, as if an object had found its way into the roof cavity and would periodically hit the underside of the roof. Not a metal on metal sound, more akin to a muffled baseball on the living room floor sound. No missing coffee mugs left on the roof, no feathers, bits of fur or other indication of ill fated stowaways.

The clunk corresponded with inertial shifts during highway driving, such as lane changes & deceleration. Occurred sporadically, but enough to get me to pull off the road and inspect the moonroof assembly for missing/loose parts (none found). The next step is to get a small mirror and a bright light and look into the rear of the roof cavity with the roof partially open.

Any ideas?

 

May be something loose, which may be hard to isolate. Good luck!