No, it wasn't on gas. So far we have come up with the theory that the manifold had leaked, which I am told is a common problem; and that the car had been left for some time, allowing the combustion chamber on the exhaust side to rust, which created the sealing issue. When we pulled the head down, the valve face on cylinder #3 (that seals against the seat in the head), was pocked with rust rather than smooth and clean. The head reconditioner rang today and said the head was also cracked, so he thought that it had been overheated at some stage too. All great news, continuing on a great week all round! Ah well, I'm in too deep now, so I've sourced another head and am having them reco'd so I can finally get on the road. The up side is that I have learnt a lot this week, and HOPEFULLY should have a reliable car (touch wood) At least parts are cheap for these cars, should anything else go wrong.
Cheers,
Dom