over heating? why?

[dpmcf]

in short- my clio 1.2 98 was overheating, i bust a timing belt last year- and i replaced all valves/gaskets/seals etc. then a year after it has started overheating with the warning lights not showing. and now it has sprung a coolant leak at the head gasket- i just removed the head and the has torn apart at the gasket allowing the coolant to leak out of the side of the cylinder head block????

is there any reason why the oil and coolant become presurised(but not mixing)- when the radiator is good and the thermostat works

one friend said that the head might be warped from the timing belt break, and the water is becoming pressurized?

Im confused!

 

[sideways danny]

did you loosen the head-bolts in order, or just one end to the other? That could make the head warp. I'd be surprised if it's something from doing the job previously though, a year is a fair amount of time. get the head pressure tested for cracks