Just purchased a golf mk4 not long ago. And was driving and heating kept going cold and warm didn't think nothing of it but then car started idling rough so checked the water and was greeted by a lot of steam so filled up and drove home about 10 miles and water was gone? Checked the oil cap and it had cream on it so I'm guessing heat gasket. Was smoky when drove off. But would a water pump failure cause headgasket to go? Have a strange feeling it might be that but not sure. I mean AND that. Any help appreciated .