Duckhunter18

https://www.facebook.com/100000568572699/videos/4268436616518582/ Anybody else experienced this? Very disappointed that I'm having issues like this before the first oil change. Had 2 separate service managers say that they've had to replace all the lifters in a few low mile '21s already. Guess mine is the next on the chopping block

Truck ran fine this morning. 1500 5.3L V8. Went to go start it up this evening and heard a loud knock. Shut it down immediately. Video is from the 3rd startup. Decided to drive about 2 miles to the dealer, techs were home but they scanned it for me and said it was throwing a "misfire cylinder 4" code. The knock got quieter and quieter as things warmed up, eventually becoming nonexistant. I'm sure it will be back in the morning. What do you guys think?