Well I have had this noise coming from my engine for a while. Just wondering if there were any ideas about what it might be. It is a fairly consistent knock/tick noise. 99% sure that it is not an exhaust leak or any kind of valve clatter. Also at highway speeds sometimes it gets a miss that you can feel pretty strong in the truck. I am thinking it is a stuck lifter. I have tried pouring three different things in the crank case to unstick it withouy tearing into the motor (gunk stuff, chemtool stuff, and phillips 66 trop art with some other stuff i cant member the name of right now) Anybody have any other ideas of what the problem could be? Or how hard this is to fix if I have to take the manifold off? It is a 95 ford, 351, 113000 miles. Thanks.