i have a pfaff creative vision and that sucker sounds like a train is running. for the price i paid for that machine it should just purr. i had trouble with mine knocking to and took it in they found nothing, than it started to grind and took it back in and that time they sent it to the complany, witch turned out to be a long story but 3 mos. later i got a new machine back and this one to is very nosie and does not sew like i think it should . but im not going threw all the hasel again of sending it in till it dies.