is the malfunction??? i put a gallon of coolant in every 4 days.....i just put a new water pump in and had the coolant system pressure tested. The test turned up no leaks....
A pressure test will not reveal all the culprits. The radiator cap may be bad, They have to remove this to perform the pressure test. They also have to wait until the engine cools down. The thermostat may be stuck and you're "boiling" out the coolant. Have you checked under the car after driving it to see if you can see anything dripping? That's the most revealing test you can do. If you cant see any drips then it's either a head gasket blown or a cracked head. After driving it park it on dry pavement or concrete, some place that doesn't have spots on it already, then back it up just enough to look for any freshly wet spots. If you do then you only have a leak, maybe the water pump didn't seal correctly,which can happen if you don't, then get the checkbook back out it's head time.Good luck with it
You aren't gonna like this but: it is probally burning it... either from an intake manifold leak or a head gasket/cracked head... either way you need to go to a repair shop and have coolant checked for traces of hydrocarbons in it. If it isn't this... it HAS to be leaking somewhere, the stuff just doesn't evaporate.