Our machine has ~1000 printing time on it. I just solved a sound similar to yours just today. It was only left to right and had gotten progressively worse over the past few months. I oiled the bearings at the end of the rods top back left/right. Try oiling them and moving it manually (Machine off). If it's the bearings, you'll hear it when you move it by hand. Since it was coming from both left and right sides, it was hard to pinpoint. I used a syringe to get oil right at the top of the bearings, then moved the head to make it spin and work it in. Might as well hit all 8 of those bearings and all the rods while you're there. Hope this helps.