car came into the shop for a bottom end knock 01 mustang gt 27000miles on motor. talked to the guy. he stated a "buddy" of his retap one of his spark plug holes in the head for him.. well guess what 2days later he hears a slight knock from the bottom end of the motor. we got the motor outta the car guess what we find??? ol "buddy" didnt vaccum out the head. shavins got into the cylinder wall jammed the piston up bent the rod crank slammed into the piston skirt