I used to clean my old Kenmore myself....but with the new esp. the computerized machines...it is recommended that you take them in for a technician to clean and check them. They can clean them down deep inside where we can't get into them... Don't blow in your machine...you will get little rust spots from the spit. With many machines these days costing $$$$$ i think it is good to take them to a skilled tech.
As soon as I finish this next quilt top...my machine in going in for a cleaning and check