Ok-first thing to do-with the engine cold,fill cooling system.leave off the radiator cap and start the engine.while you start it,watch the radiator where the cap fits-if you see coolant immediately shoot out with some force,a head gasket or a cracked head.also look for water in the oil.this will be evident by droplets of water on the dip,or oil that resembles a chocolate shake from mcdonalds.also you may see milkshake on the inside of the oil filler cap.(all bad news)! but be of good cheer-these engines are pretty tough. if none of these then you may have the t-stat in reversed.also if the t-belt is not exactly on the money,this will mess up the timing and also make it overheat. also make sure both fans work or the fan works 2 w/ac 1without. also blockages in c/s . good luck