Mayo in Oil and Water - Inlet Manifold?

I may be clutching at straws here, but I recently got halfway through replacing the inlet manifold gasket on my 2005 TF before realising I had ordered the wrong gasket so put it back together. I loosened a couple of the manifold bolts but didn't remove it. Approx 50 miles later and I have Mayo in the oil and water. Is it possible that this may have occured due to dislodging the inlet manifold which allowed mixing of the oil and water or am I looking at HGF?



I know which I'm expecting it to be but was hoping I might get away with just the inlet manifold..................



If it makes a difference i was swapping the inlet manifold to try and stop a persistant (but slow) dropping of the coolant level.



The car seems to be running fine and there is no sign of overheating.



How easy is head gasket replacement for the home mechanic (I think of myself as pretty competent having rebuilt, and maintained, a couple of classics over the years).



Thanks,

Dave

from the last news http://ift.tt/1yhSdfT

via IFTTT