for starters, i sympathize with the broke student problem, but you need to put a little money into the car. first, since the coolant is a rusty/brownish color gunk type stuff, flush the cooling system. you will be replacing the coolant anyway if it turns out to be a bad water pump. as for finding the leak, would help to know what motor is has...since you are mentioning the intake, i would assume it is a 3.1/3.4. locate water pump on engine(standing on passenger side, looking at engine pulleys and so on, is on right hand side). feel under the pulley(MOTOR OFF), and see if there is any slime/residue there. if so, confirm pump is leaking from weephole, and the pump is bad. is leaking from gasket, may just need new gasket...but pumps are cheap so might as well replace anyway if gasket is leaking. also, look at lower intake manifold where it contacts head(all 4 corners). if gasket is leaking externally, you will see trails of fluid residue running down heads. if it is leaking internally, you will have coolant mixed with oil. keep an eye on it. post back what you find.