Answer to "Why fan is making loud noise when it rotates"You need to disassemble unit clean the front and back bushings and lubricate with household oil. Remove fan shroud, blades, and back plate. Remove oscillating pull button. Remove plug on back cover to access screw. Remove screws holding the cover. Remove cover. Remove oscillating mechanism. Remove back plate to access motor. (4 screws with nuts). Remove back motor plate. Clean back bushing and lubricate with household oil (not WD 40) Lubricate outside of motor. Drop oil on front bushing work back and forth. If still binds then remove T pin clean and lubricate front bushing. Re assemble and should work fine. My 1655 ran continuously for about a year before it started binding up. Takes about a half hour to fix but now it is smooth as butter again.