Toyota Repair: overheating 1992 previa, coolant leaks, engine coolant

Question
previa 1992/198,000kms

radiator replaced...thermostat replaced...still overheating. needed to turn the cabin heater on to dissipate the heat from engine. coolant boiling when overheating. fan seems to be ok when manually turning,  but thinking of replacing fan too...fan continuously running. is this normal?

please help...

Answer
The problem may be a blown headgasket and I recommend that you have the engine checked for that possibility, any toyota dealer can do this, it requires some special tools but it will eliminate or confirm that as a source for the problem, also I would suggest pressurizing the cooling system to see if there are any external coolant leaks, I assuming that the the fan belt has already been checked and the fan is spinning when the engine is running.