First post with a new-to-me truck; 2016 2500, 64000 miles and my first diesel. Traded up from a 1500. Bought it knowing it had an issue, had the top end rebuilt; shaved head & new gasket, ground valves, new seals, the works. Only issue from the rebuild is it now has an exhaust leak upstream of the turbo; only noticeable when the exhaust brake is on. Going back to the shop next week for that to be fixed, on them of course. It had a tick when i got it which turned out to be valve lash, but now i'm noticing another tick since that one is gone. Posted a video but it is louder in person. Always there whether the engine is cold or warm. Quick search here didn't yield many results, or maybe i'm not looking in the right place. I plan on asking the shop what they think, but would like some assistance narrowing it down before going there. Anyone encountered this? It's not the DEF system, heard that ticking the other day.