I have had my XCT for about 3 1/2 weeks now and just took it in for the first 500 mile service yesterday. This morning when I started it, I heard a knock for about 2 seconds then it smoothed out. After that it ran fine and started without any noise. This is the reason I got rid of my HD because of bad lifters and all the valve train problems they have. Anyone experience this? I'm hoping it was a one off occurrance. I am waiting until tomorrow to re-crank it in hopes it won't do it again. Any help would be appreciated.