i was wondering if it was noise related, cause thats not a good sign. its common for the crank pulleys to come apart, mine and many others have too. take a close look at the frt of the pulley. if the rubber ring looks tattered, its likely coming apart, and that causes belt noise.
if you look at the groove side of the belt, little tiny cracks in between and across the ribs is actually not bad. if there are any little chunks chipped out of the ribs, 1/4" or longer it is bad. if you see cracks running with the belt on the smooth side, also bad.
check the lines on the tensioner bracket too for stretch.
05 V6 auto,
"The V6inator" torch red, base, amustangrocksleather padded leather armrest, shift boot and e-brake cover