Coolant dissapearing !!!

[Barney_Barney]

Over the course of about 600 miles the coolant level has dropped below min in the expansion bottle, only requires about 1/2 litre or the contents of the expansion bottle to fill back up. No pools of coolant under car after standing. Car is not overheating and no temp fluctuations as per the gauge, engine runs fine, no residue of oil in water or water in oil. My only fear is that it might be the sign of head gasket on its way out, is there any other glear sign of head gasket trouble other than checking for sludge in the oil?. Im reckoning it maybe a small leak under pressure some where in the water circuit...Is there any weak spots worth checking first on the water circuit, any suggestions....Car is A 03 V70 T5.

[MadeInJapan]

Yeah...check everything, even the water pump which might be starting to weep a bit. Also, take the expansion tank out and check under it for leaks (lay a paper towel down to see if it absorbs any green liquid). I had a similar problem and it was the large upper hose to the radiator, and another time, it was the small expansion tank hose that connects to the thermostat housing- found a little residue around that housing and that was it. In either case, hoses just weren't fitting exactly right and there was only a dribble...hard to even notice it until the coolant level did like yours. Mine was on my S70 but all of these cars can have many of the same symptoms.