Im no expert (obviously) but given that i can drive 30 miles without incident (albeit with the needle reading at about a quarter) i cant help feeling this is an intermittent thing.
How long would it take for new coolant to be, well, sniffable? Got in it this morning and within three miles the needle was heading up and up, so had to use the stinky work 90 for my 85 mile round trip to the builders merchant. Got in it this afternoon and over the same three miles the temp was only beginning to reach the dead centre. The hoses werent to solid, right one (top?) hot, left one warm, levels good etc. Bet tonight, itll go straight for the red.
Surlely if head / block / liners gubbed then the problem would be there ALL the time?! Also t'was me who had new stat put in. theres a whole world of black sealent around it and i have noticed some weeping from there. Pretty sure Land Rover didnt send these things out the factory with silicon smearing part of the manufacturing process!
i'll sit it in a dry workshop tonight and look out for leak...