a very simple test,, based on ma on experiance,, put ur radiator cap off and start ur engine,,make sure that radiator is teemed with water,, now push the accelerator,, if the water comes out on pushing the accelerator,, then there can be two faults,,
1) radiator
2) gaskit,,
now go to any radiator wala and ask him to install any other radiator,, and devise the same process,, if the problem remains there,,i.e,, water again comes out by pushing accelerator than there is gaskit problem