Just to refresh your memory I got 8 litres of oil mixed with antifreeze when I drained the oil so I assumed I had a blown head gasket. I should have done a compression test at that point but I didn't. I added fresh oil and filter and ran the motor for a minute or so (no coolant in the block) to flush out the crap mixture. Finally got around to pulling the cylinder head and much to my surprise the head gasket appears to be intact? There is no evidence of a blow out anywhere? The cylinders look dry and there is only light carbon on the piston tops. Is it possible to have a head gasket leak because some head bolts have loosened over time resulting in a leak that does not necessarily obviously show on the gasket? Or does this mean that one of the figure eight gaskets has failed? I sure hope not . I will check the liner protrusion for the correct height above the block but I believe they are correct.Two of the spark plugs were black carbon. The other two were black with a sort of an oily sheen? Unfortunately I did not keep them in order when I removed them to see if the two shinier ones were side by side. Any thoughts?