Help Overheating problem

Hello everyone hoping to get some advice. In December we bought a Range Rover 2.5 DSE Auto. Everything was fine for a couple of weeks, then after a short journey the temperature crept up and the warning light came on. We stopped immediately. We let it cool and topped it up with water, and carried on. It was then fine again for a about 3 weeks then same thing happened again. The mechanic pressure tested the cooling system on the engine and found a split hose at the back of the engine that was leaking a small amount of water. So we replaced that. It overheated again, about a week later, he pressure tested the cooling system again, and found water leaking out of the side of the engine, from the head gasket. We then added K-Seal to the water, which is a permanent gasket repair, it has now stopped losing water, but is building up pressure in the cooling system very quickly when the engine is under load. But it will sit ticking over for hours at running temperature without overheating. Any advice on what to try next would be appreciated

Hi, welcome to the forum, you'd be better off going into the range rover section of the forum and doing a search for things like overheating, cooling system pressure build up etc. I'm sure there will be loads of results to pore through. If not, raise the issue with those that frewquent the RR section, there is a lot of experience to be found but you will quickly find, sometimes in a rather curt/unkind manner that raising issues in the welcome section on your first post is frowned upon.
Other than that, very best of luck with the Rangie, hope you get it sorted, I'd love to own one so stick with it!

:welcome2:to the madhouse and what DiscoTony said