If you are smelling it from the exhaust, you have either a cracked block, head, or blown head gasket. Easiest way to tell that is with a compression test. make sure all the cylinders are approx the same. If you have a cylinder with much less compression that the rest, that could be the problem. Also to a pressure test on the cooling system. It should hold 16 lbs or what ever the specification is. If it doesn't you have a leak. 1/4 of an inch isn't very much. I'd think if it was burning coolant, it would be more than that. My guess is a leak somewhere and after it warms up the engine heat causes it to evaporate.
'08 1500 Ram, Quad 4x4 Bighorn, Silver, 20" wheels, 5.7 Hemi/MDS, 3.92 axles
"Meddle not in the affairs of dragons, for thou art crunchy and good with catsup" -Doc, IFSJA