Alfa Romeo Repair: alfa romeo 145 engine coolant, water pump impeller, alfa romeo 145

Question
i have recently aquired a 145 2l ts(p reg). the first time a baught it the coolant overheated and the engine temp was really high... i then drove home and the con rod went through the side of the engine.... this was on the way home from buying.. i then had the garage i baught it from repair the car. on the day it was returned i drove the car 50 miles and the engine overheated again... cause the engine coolant to boi over a cause a great amount of steam coming from the coolant resivoir... do you have any suggestion...
my head tellsme it must be some sort of relay or sensor for a fan or to turn on the water pumps that is not regeristing.. please email me or contact and that will be most greatfull.

Answer
Here are the parameters to deal with. If the overheating occurs only below 30mph or when idling in traffic then the problem is with the fan not going on for some reason (like a corroded connection--a burned connection if caused by corrosion). If the overheating occurs after more than 6 miles then the problem is with the flow through the radiator or a bad impeller in the water pump. Overheating between these 2 items will probably be a stuck thermostat or faulty water pump impeller.  You may also have an air lock. If the heater does not put out hot air then the coolant level is incorrect or there is an airlock.