My oil is smelling burnt, It is a quart low, and it is smoking, not all the time, my every once in a while. Any Ideas? The oil only has 2500 miles, and i've been using Valvoline DuraBlend 5w30 with Fram Tough Guard Filter. I don't think the pcv valve has been changed (to my knowledge) and I know the egr valves haven't. I know the 4.7 has a sludge problem, but I haven't noticed anything when I have checked it before. Please help with any suggestions..I am sick as can be worried about this. Thanks!