Sorry to disappoint you but you get what you pay for. Singer today is not the singer we grew up with. Today's singer is one of the cheapest most poorly built brands. It is NOT the same company that made the great machines here in America that still sew well. It is just a name put on really low quality machines to boost sales. If you got 4 years you're lucky. You got more than your $ worth. Get a new machine, or a new-to/you older machine & be happier

When my machine did that the lint had jammed up inside the feed dogs from several years of sewing and I had to have the service man take it apart to get it cleaned out....it wasn't something I could do at home.

I have a singer 7442 and it only takes oil in the bobbin case.