300,000 Stitch Tune Up

My sewing machine is currently screeching when the needle plunges into the fabric, much like a Psycho film.  Blah.  I don't know where to oil it, which is what I'm assuming it needs, but my manual says not to oil it.  Boo.  And then there are tension issues, problems with the quilting foot, and skipped stitches when I try to zigzag:

I'm assuming it needs a check up.  Its last one was about four years ago and I have since made tons of things, so I'm definitely overdue.  I've got about two projects to finish up this weekend and have begged for some time away from the kiddo in order to do this.  I could sew during her naptime, but that screeching is sort of unbearable and I don't want to wake her up.  

I'm going to drop the machine off at Treadle this week and it will take a week or two to get it back, so I've got to work on some hand sewing projects in the meantime.  Plus it will give me an excuse to keep my feet up.  I noticed some ankle swelling over the last few days.  Stupid pregnancy.