lol, wow, I would just ignore most of these posts. Burnt valve would cause some other issues, like running on 3 cylinders...
Sounds like a head gasket to me. How's your coolant level, is it going down, and are you getting any bubbles in it when you take off the cap? Check the oil too, is it milky? Milky oil is a sign that water has mixed in with the oil.
If it's really bad you can actually blow your motor by getting too much coolant mixed in with the oil. A compression and leakdown will give you more insight into the actual issue.
efhondakid has it right, blue=oil white=coolant