Looks like you have a problem with either sensors or thermostat etc. If the system gets too hot then water will leak out. It may not obviously boil but is too hot alot of the time and it doesn't register internally. However My Wife's 145 leaked water at times for no reason even after she got a new engine. After checking everything the only thing that fixed it was "stop Leak" additive to the water. Try it it could be the solution you need?
My advice for now. Check the thermostat, the tempreture sensor and then if okay put in additive..