Vanishing Coolant

[spryn]

Hi all Ive had my carnival 03 auto since new its done 31,000kms and everythings been going good untill april this year when i noticed my coolant going down and there are no leaks at all.
When i first took it in they did a pressure test of course found nothing and toped it back up,2nd time emptied out 6 weeks took it back they changed radiator,3rd time emptied out within month they changed overflow,last time emptied out within month they changed radiator cap what a joke they have no idea anyway my 3year warranty ran out last week and i have it booked in for the 27th december i bet now it is out of warranty they will check gaskets and cylinder block etc i advised them i shouldnt have to pay since it is a continuing problem they said they take each case on their merits and might show some goodwill so if anyone has had the same problem with their coolant could you please let me know.
Cheers spryn:

[Inky]

Failing head gasket?

[spryn]

I hope not Christian but i think you may be right.

[Inky]

If the leak past the head gasket is slow enough, you may not even notice it aside from the vanishing coolant. Keep an eye on the tailpipe (white "smoke") and oil (chocolate-milk-shake look).

Let us know what you find out.