1.check your water pump, if you`ve never change your water pump.for goodness sake change it, you would be happy to see that the water pump is rusted and harder to spin compared to the new water pump.
2.change the radiator pipe if you need too.if the pipe is brittle change it ASAP for a good piece of mind.
3.service your radiator la bro...its not that expensive,But if you think that a new radiator is much more worth buying then yeah its your decision anyway.
4.i do agree with "craziqbal" it could be your fan that is defective
5.do check your radiator cap, just in case the rubber is weared off