Razz just like you did with the belt squeak, get it on video first to start documenting it. You are on the same journey I was on, it will be helpful to the forum when you find your fix. Time to start trying different stuff.
That is what all dealerships say, azzholes that they are. Here are all my ideas on the subject.
One, the high moly ester base light 5w20 will help, currently either redline or Motul. This worked for me but I keep in the back of my mind my knocking may come back, so the rest of my backup plan as follows.
Two, if that didn't work you could "TRY" going to 5w30 with the same oil. Personally I believe 5w20 is better for noisy lifters, but there is some evidence 5w30 is also a good choice. I don't know or understand the science behind that, but I've read several places this is the case. Most of the time going thicker is a bad idea, but some hemi's respond to it. IMO, I would still try the high moly 5w20 first, but as a backup if that didn't work I would definitely try messing with a slightly thicker oil. Yeah it would be a hard pill to swallow after shelling out for a 100 dollar oil change, and still only might work. But bottom line you could wait before trying the next thing, like run redline 5w20 and live with that for 5k even "if" it didn't work, then try the 5w30 of the same brand.
Three, if that didn't work you could start in on different oil additives, think of this step as your hail marry. Learn about the additives first before dropping them in your truck. I would try Cerma before other additives, and maybe marvelous mystery oil. However, I had run MMO in mine before i went to Redline and it didn't help the knocking at all.
Option B, live with it a lot of guys do. Bottom line you are under warranty so if your truck breaks down you have a warranty.
Option C, get an independent shop to state in writing you have faulty lifters and sue the dealer and manufacturer.
Option D, just try a cheap 5w30 before any of this, just maybe it will help. Actually there is no real downside from doing this first as well and is a cheaper option then going with redline. Bottom line if it didn't work you know you tried, and you can always dump it and go straight to Redline 5w20. it would only be 20 bucks or so and is a decent place to start if you were worried about costs.
Don't know what else to say, but been there done that and good luck.
Kreen is a cleaner by kano labs, whatever you try if and when you want to start from a clean slate, that will get you there. But your truck being so new, I doubt you need this at this point.
