I've read several posts where people have complained that M1 was causing there valves to tap. Can oil effect something like this? I had this problem a few weeks ago and it has gone away. I can't say for sure it was the oil, but I'm running Amsoil now and curious if it was. When I switch back to M1, I guess I will be able to tell. I personally don't think it could be from the oil. Any thoughts?