I'm still trying to diagnose my cooling problems and I wanted to start with the radiator because it seems most likely the culprit. If the top hose is hot, but the bottom radiator hose is cool that should mean the radiator is doing its' job right?
Sounds like your Tstat. How's the heat (climate control I am speaking of) in the car?
Regardless, you would have to take the radiator out (easier if you do, but not necessary), attach a hose to one end and start spraying. If the water on the other end just trickles out slowly, then the radiator is clogged.
The heat in the car blows nice and hot. I find when I drive the car if I don't have my efan on and the heater blowing it gets too hot. I figured that would point to it being the radiator. Also, I've flushed the radiator a few times using the drain plug and when I flushed it with water it poured out nicely. I wondered if maybe the radiator wasn't just partially clogged, which was why I wanted to see about doing a more accurate test to check.