The machines I own are also sealed and not for me to oil. Even though I keep them as clean as I can within the areas that I have access to, the professional servicing/cleaning of the machines includes areas that I can't get to; plus they are oiled or whatever when they are serviced ... I know this because they sound much quieter when I get them back home. The dealer to whom I take my machines to be serviced will allow me to make an appointment so that it's only gone for a couple of days, rather than a couple of weeks (w/o appointment). He always forgets something, though, and I learned long time ago to leave notes with him about what is not right and even then, he forgets to do everything. Makes me crazy, especially considering the big bucks he charges me! Because he is just a 10-min. drive away from my house, I buy brands of machines for which he is a dealer, altho' that changes from time to time. He just got his first shipment of Baby-Lock yesterday.