Did you just put the rig together? I ask this because it may be the mobos temp sensor reading wrong. If your CPU is that hot, then the water block should be hot to the touch also, assuming that the waterblock is making good contact. Touch the water block on the base when your rig is running. At those temps, it should definitely be noticeably warm atleast. If it's not, try pushin it harder against the CPU. Just add a bit of pressure to it, aimed straight down on the core, and see if your temps drop. If they don't, then it may just be a messed up thermal probe.

If your block is hot though, then the radiator ain't doing it's job. Might be flow related or just a crappy radiator.