I have an '03 6.0 and had a coolant flush on it 3,000 miles ago and haven't checked it since. I just checked it and it looks a little low (about an inch below the min mark, also the truck was cold and shut off when I checked it), anyway, I don't have much for residue, just a little spot here and there, so super minimal. Where could I be losing coolant? If I'm not mistaken it would be puking if it was an EGR cooler or head gasket problem? Any insight is appreciated, thanks!