Just thought I'd close the chapter on this (as far as I can !)
I removed the head and took it back to get it pressure checked. It came back as no problems found.
Examining the head gasket I could find no obvious sign of leakage, however I did find two of the head bolt holes in the block had about 2 inches of oil in them. This made me think that potentially this had prevented me torque-ing the head down properly, so I thoroughly cleaned everything up and bought new gaskets, got the head surface checked for flatness and put it all back together again.
Result ? Clouds of white smoke after about 5 minutes and coolant level slowly going down
What gets me is that coolant is entering the combustion chamber (to come out of the exhaust) but is also entering the crankcase, as if I take the oil filler and dipstick out, steam comes out of those orifices as well ! I even disconnected the rocker breather pipes to make sure that steam wasn't being recirculated into the combustion chamber through the plenum - but it made little or no difference.
Finally last weekend I took off the oil heat exchanger, connected it to the garden hose and pressurised it with water, looking for leaks. Result - nothing, no leaks at all.
As far as I can tell, that is probably the end of any "cheap" to fix lilely problems ??
So, I can only think that either:
1) There is a crack in the head that only opens up when hot
2) Theres a crack or porosity in the cylinder wall
3) The block surface is warped so the head is not sealing properly when the engine heats up
Unless anyone has any better ideas, I guess the engine will be coming out and a replacement going in. Anyone got a cheap 1.8 TS CF3 ??
How difficult is it to get the engine out ? I understand it drops out from underneath, but is it a couple of hours or a couple of days work ??
I've started, so I will finish !!