I have a 2012 focus se with 140,000 miles. It developed a knock on my way home last week. It doesn't knock at idle or accelerating . It knocks when decellerating in neutral or light loads. Clutch doesn't have any effect on it. As well as turning. I pulled the serpentine belt off and it still knocks. Checked timing belt and pulleys and pulled valve cover off. Everything looks good. I drained the oil...no metal in it. Also replaced the CAT and verified the mount was good. I'm out of ideas. It almost sounds like something is loose. I thought something like the flywheel was loose but I would think using the clutch would effect it.