if the upper hose is hot and the lower one is cold, either the rad is clogged up or the water pump is really shot to hell, like the impeller is rushed to death.
pull the upper hose off the rad, and the lower hose, either off the engine or the rad, then fill the rad, via the upper hose hole and hold your hand over the lower hose to hold the water in the rad, when its full let the lower hose go, the water should fly out fast, if its not coming out quickly id think the rad has a clog.
if the water is fly's out, then the pump is most likely shot.
the water pump costs 40 bucks and a hour of your time. a simple 30 piece socket set is enough to do this repair. is easy.
the rad i think you could get for 150 ish, or less. i have not bought one for GP but have for other cars and truck and they don't cost all that much. and thats a easy swap as well.
