check your hoses may have a leak in one... also is one or both hot or cold after running the car..
and check your radiator, i kept losing coolant too... turned out to be my radiator, put a new one in and no more problems
yeah both coolant lines are the same temp, I took the thermostat out so its constantly moving through the radiator, plus the fan is always running.
I have a spare radiator, so Ill try to and check it ou.