I can see diesel cooler in that video so I'm assuming we are talking about pre-facelift 3.0d? These have solid flexplate so unlikely to fail. (Compared to riveted flexplate on the newer models.) Though it could be loose bolts between flexplate and torque converter. I think these can be checked via the opening at the bottom of bell housing.

If that sound comes more from the front it can be caused by failed vibration damper (crank pulley).