Hello all. I’m a new member and this is my first 1500 gasser. Coming from a long history of Cummins trucks. Truck has 36k on it. It has developed what I consider a metallic knock/tapping on cold starts. It is rhythmic with rpms. I have done a lot of research and watched a lot of videos and this does not sound like the normal hemi tick or exhaust leaks. I’ve had it to the dealer once already because my exhaust bolts rusted and broke and I asked the dealer to look in to this knocking/tapping noise as well. They fixed the exhaust connection and told me the sound went away. Yeah ok clearly not the case and the 2 problems are not related. I have numerous videos from cold starts to document the problem. The truck also seems to be down on power, I notice a hesitation under acceleration and there is audible spark knock/detonation. I do plan to take it back to the dealer but any input on cause? I’m thinking lifter/cam failure…link to video is below.