Quiltingboard Forums - Question Juki 2010q

Hi...I have a Juki 2010q machine that sews fine when sewing regular cotton material. But I am making little mats with two layers of fleece and a couple of layers of polyester batting and my machine is making a slight squeak / knocking (for lack of a better words) sound. It is not a sound that you know you should stop sewing right away but a slight annoying one that worries me. The stitches come out great however. I have seen videos where the Juki 2010q can sew through many layers with no problem. I clean and oil the machine often and I put in a new needle and re-threaded the machine and checked the bobbin thread. Also it was serviced fairly recently. What can I be doing wrong?...by the way I have sewn the mats before and I don't recall this sound. Also, it seems to happen with the walking foot. Thanks.