I have a Ford Puma 1.7v 1998 and there is a gurgling noise coming from the water tank. The water light came on the dashboard and my uncle said it was the screen wash needing replaced. We replaced the screen wash and the light went off, however I was driving to work this morning and about 10 minutes in, the water tank started making loud gurgling noises as if the water was boiling inside the tank. By the time I opened the hood it had simmered down and when I felt the water container it wasnt even warm. What is wrong with it?