Yep, just had to tighten the nut on the bottom of my EGR valve for the same reason. From reading about the symptom and cause on this site awhile back, I expected that the nut must be somewhat loose when I started to hear the dieseling sound coming from the engine bay, but I sure didn't expect it to be backed out of the EGR valve ALL THE WAY, and simply wobbling around on the tube about two inches below the valve!

Anyway, nut has been tightened, and no more noise.

Incidentally, the change in operating conditions with the nut tightened was enough to produce a check-engine code/light on the dash. I reset it by disconnecting the (-) battery cable for awhile, and so far it hasn't come back on.