i am a member of RAC recovery. i called them and the mechanic come and checked the car.
few things he checked after i told him about the heating problem
1) he open the radiator cap and filled in some water, it was pretty ful few hours earlier but i think he half litre in ( half litre is gone missing in engine some where)
2) he looked around in but he didn't find any external leaking, he goes, if any pipe split or radiator problem then it the water leak will be slower but as i told him, it lose water like 5 -6 litre a day. so he goes water is going somewhere inside the engine so he goes its internal leaking.
3) from the exhaust pipe, water is dripping slowly and hence engine is hot but still white smoke coming out.
4) he said, it can't be thermostate or radiator because it wouldnt lose water that quik so he goes either its headgasket or water pump. but he goes, he think its head gasket is gone.
5) i asked him about compression test, he goes there is no need for that. you need to do CO test instead.
he goes, head gasket or pump is still a big job to do, if you will get it fixed, the mechanic will have to look all the bits like pump, pipes etc so it cost you around about 600 - 800 quid.
i am so worried because i only bought a car few days ago. is there anything you all can think of?