Sure it could be a leaking head gasket but that would be a lot less common. You may be able to verify that with a chemical test at the radiator. With the engine running, air is drawn through a glass cylinder with two chambers partially-filled with a special dark blue liquid. If combustion gases are present that liquid will turn bright yellow.
If you think coolant is going out the tail pipe, the dye will show up there too.
Wednesday, March 20th, 2013 AT 3:39 AM