When mine was newer, it would rattle a little every so often. It's quiet now, except when I change the oil, then it will rattle for a second until the oil pressure builds up all over. I put a little oil in the filter to help prime it but it still takes time to build up. I always used the FL820S after I learned years ago how crappy the Fram filters are. Tour # 2 rattled from a cold start no matter what I did. They were built a few weeks apart.
