Rattling (or is it knocking) sound between 3 to 4k RPM

[Wag]

You should cruise at a minimum of 4500 rpm and in 6th gear, that's about 85 mph.

Downshift that bad boy!!! Make that engine SING, brother!

--Wag--

 

[BA BUSA]

It actually rattles all the way to 8k and it does it in all gears. 3-4k at 6th is where it does loudest. So, I just seeking help to understand this abnormality so that I can correct it. ???

You should have said this sooner...try a different brand of fuel...at least two tanks and then report back.

 

[wv rider]

During the break in, you really should not be lugging it. The most important thing is to get the rings to seat. From what I am hearing, I would take it back to the dealer. My truck sounds that when I put a hard load on it. My truck also has around 200,000 miles on it.