I have a 2018 Exp Max Limited with HD tow package, 77k miles, we bought used in fall 2020 (and no extended warranty). I had the oil changed about 2 weeks ago and right after that, I started getting this odd noise when starting. Hum...so a quick google search has lead me cam phaser issues, and yep, it sounds just like the videos I've seen. I don't have any check engine lights on, yet, but would like to get ahead of it. In light of having a recent oil change (at quick lube place....I know probably not the best choice), it could be coincidence this started right after that, but any chance it could maybe be related to the oil change? Since then, feels to me like it's idling rough. My local dealership's service dept is terrible, but that's likely who I'll take it to.... I saw a video about priming it with oil before starting - haven't tried that. I need to tow a horse trailer about 2 hours away and back in 2 weeks....I don't want to be left on the side of the road. Ugh. Suggestions from those of you that have had this issue, which sounds like plenty of you??