Just changed my oil in my 2003 GMC 2500HD 8.1L with 119,000 miles on it. I use valvoline high millage(red bottle) 5w-30. Smelled the oil like always ha! and noticed it smelled a little burnt. Buddy told me could mean burnt valve(s). Any truth to that? Truck has beeen running fine and haven't noticed any burning oil smell when I'm driving.