After my rolling road session today, I decided to do a compression test to make sure everything is in order, and got 208 psi on every cylinder. As far as I know thats good.
The reason I did this is because recently I have noticed that there are little "lumps" of white mayonase floating in the header tank, and there is an oily look to the surface of the water. If I mix it around a bit with my finger, it looks ok- and there are only small pieces of the may like stuff.
Could I be suffering from a porous head, and what do you do if you have one- it is a c20 xe.