Are you seeing a cloud of white smoke on start up or while running? Burning coolant it looks like that. Burning oil looks more gray. A crack in the head can allow compression / combustion gases into the water jacket. It's $50 well spent to have it checked at a machine shop that can perform a magnaflux type dye test even though the head is aluminum. The head should be completely disassembled including valves removed. There are also do it yourself preparations on the market. Here is a YouTube page with various methods.
https://www.youtube.com/results?sear...lux+head+test+