I broke down after my car overheated. Looked at the coolant and there wasn't any. Put loads in and managed to get it back (3miles away). Got home and looked again and it again no water. The next day put more water in and it started leaking out of the bottom of the car. Mechanic looked at it and replaced the cracked water housing which seemed to fix the problem. Drove 20 miles, heat coming through the blowers and temp gauge was fine and didn't rise over the usual temp. Checked the water level again and there wasn't any!! I filled up a massive jug (maybe 1.5 litre) drove 6 miles and again no water. The only difference is that there is no water leaking out the bottom (which I guess is a good thing) I'm just wondering if this could be now that there is an air bubble?? I have no ideas about cars but my other half knows a little and this is what he thinks it could be. But it just seems a lot of water going in and not staying in the tank. When I do put water in, bubbles do come up from the neck of the water compartment.