My sunroof motor sounds like a machine gun opening... I have to hand assist it the sun roof to get it going. It closes fine. I'm guessing its the clutch on the electric motor or a obstruction somewhere. I once got this noise when I left a box of stuff on the roof top and forgot about it. Anyone ever adjust the clutch on the sunroof motor or have the machine gun (clicking) noise?

 

After weeks or greasing the rails and worrying about the alignment, I broke down and bought a used sunroof motor from a junkyard. Problem solved!!! No more machine gun noise...