Over heated two months ago.Changed thermostat twice.Didn't fix it.Blew a head gasket.Changed head gasket,radiator and thermostat.Water pump is about 6000 miles and fairly new.
Now,driving for over 3 HRS I notice i still loose coolant.I have no visible leaks.No over temps,yet.But I shouldn't have to fill it up w/ half a gallon after only 3-4 HRS of highway driving.I took it to the dealer and they checked everything and they said nothing was wrong and everithing was in specs.Last shop said the same thing.Head gasket was good and nothing's wrong w/ it.Any ideas?Please don't tell me it's a cracked block.Any way I can find this out?

probably burning all that water off.. like a cracked head or something might be leaking it into the cylinders.. but normaly you'd notice teh car running like crap if that was teh case... so I don't know exactly.. just my first though.