Land Rover Repair: 98 Discovery Overheating issue, head gasket failure, engine failure

Question
I have had overheating issues with my 98 Discovery.  I have blown three different hoses. They have all been changed now except the bottom radiator.  I have changed the thermostat. I had a major water pump failure that also broke my fan. I replaced the waterpump, fan, and belt.  It seems to have blown out of every weak spot! Now, after replacing all the above, it seems to boil out of the coolant reservoir cap.  BUT the engine does not overheat before it boils over and it only happens after I shut it off.  It seems to me that there is a lot of pressure build up.  Whats next?  Is there something I can do to make the engine run cooler? Different oil?  Thank You

Answer
I'm sorry to say that excess pressure in the cooling system is a sign of internal engine failure.  The full explanation is rather long but I have some articles describing this on my car blog, http://robisonservice.blogspot.com (October 2009 archive and another more recent) and on my website, www.robisonservice.com > service > land rover > articles.  You could be looking at a head gasket failure or a liner failure within the engine block.