Hello!
yeah possible reasons are!
@)Radiator needs service from inside or radiator Fins chowked..
@)Get fresh water and make sure there will be no rust left inside as somethimes rust deposits are badly created causing water to restrict.......be get it coolent mixed
@)check fans and Thermostat that its working properly.......if they are causing some problem...get them run direct.......
@)last and final.....Head Gasket needs to be replaced....
Thanxxx