There's a good chance that if you'll remove a couple of drawers and look around the sides and back of the micro that there is something rattling against it such as wiring, cable or the copper propane line. The other problem is that Airstream installed the micro in the cabinet with no cushion under it at all, it sits directly on the hard wooden surface. I went to Lowes and picked up a pack of rubber cushions (4) with an adhesive back made for furniture legs, maybe two and a half inches in diameter and 1/4 in. thick . Place them under the micro and it will be much quieter. it its easy to remove by removing the screws around the front. I recently discovered another culprit, it sounded like the glass dish in the micro but it turned out to be a heat shield rattling against the exhaust pipe for the heater. It very elusive and would only rattle when hitting a good size bump. This thing has had more rattles than I could have imagined but after several months I think I have fixed them all... for now anyway.