As you say, they aren't always evident.......

I know its easy to say now but you should of had a pressure test done

I know its a pain in the ass but i expect relaistically it will be the head and its an easy change on a CVH.

Just keep an eye on it for now......if theres oil in the water, water WILL appear in the oil too.

I wouldn't rely on it for time being though you don't wana be driving it too much otherwise it will be bottom end and a new turbo aswell