I have two places to oil my machine. I have a Janome 10001
Under the bobbin a tiny hole with felt
Where the needle bar goes up and down there is another felt pad that needs to be oiled. You have to open the front cover to see it.
I clean and oil my machine with every bobbin change. I live in a very dry climate. I take my machine in once a year for a good cleaning, adjusting etc. once a year. Never pull your thread out from the top; always cut it and bring it through the needle. This well help keep the tension disks clean as well as the rest of the innards. Thread has a grain and if you pull it out from the top you are leaving thread "dust bunnies (lint) behind in the innards of your machine. There is a little thread waste doing this but well worth it to keep machine up and running properly and no tension problems. I was taught this many years ago. My machine tech tells me every year what great care my machine gets at home because it is soooo clean when he opens it up. I told him my tread trick....he told me it was true and that most macines are in the shop because of the lint build up and not getting enough home care. If your machine keeps squeaking get it in the shop!
Connie1948