Hello Leslie,
Increase the pressure on the foot, don't pull the fabric through, let the machine take it, for normal sewing unless you are doing very close satin stitch stitch length about 3 or 4, if you are sewing close stitches as you say make sure you have the satin stitch foot on and not the general purpose because it won't feed through properly, the knocking sound could also be the teeth knocking on the needle plate, try a large straight stitch and see what happens, top tension about 5.
drivewithken@blueyonder.co.uk, October 2008