OK heres the problem, I bought this 94 disco with a bad engine, the PO ran it so hot back last summer it blew out the freeze plugs, ( HOT HOT) anyway I decided to buy another used engine, so I got one out of a wrecked in right front 95 disco in junk yard, with 155k miles on it, (nice looking rig and clean oil too) anyway I installed it in the 94 body and drove it 15 miles ( 45 to 50 degree day) and the temp started up 3/4 way on gauge and so i pull over and see coolant pushing out of radiator, so i let it cool a few minutes and went on my way, 15 miles later same thing happen but this time I turn on heater and it cools down, then coming back home it does it again, I can rev it up and it stops, so I pull out thermostat and replace with another and same deal , gets hot and overlflows etc, I pull out radiator and replace with Known good used one and same thing! im bleeding system too! so I take original radiator to shop and they said it was plugged up so they charged me $135 to clean and rod out radiator and I install and same thing if not worse now! its rad is cooler than the expansion tank, sometimes when its pushing water out of tank the gauge is half way even, im ready to give up, no water in oil and no oil in water, whats wrong with it? sometimes the heater stops putting out heat too! seems like air is getting in it from somewhere, exzaust isnt smoking or steaming either! im at wits end, its usually doenst get but 3/4 way up on gauge and then cools back down, fan is turning and feels OK too! its now doing this even in 20 degree weather too! Help!