i had this problem w/ my 164 before it went straight to hell. but i didn't have much coolant, mostly water. your water pump should be right there on the front/top of the engine, take off the top. now take out the thermostat. if this isn't a head gasket/engine issue, which it kinda sounds like it isn't, that should take care of it. my thermostat was seized up, and making water blow all over the place. you can find a new thermostat somewhere, but i didn't look too hard, being in florida and it won't get cold here till january anyways.