Chris,

Sounds like you might have a blown head gasket. See if there is any coolant in the oil, look for water droplets on dip stick. Look for traces of oil in the radiator or overflow tank.

Have a pressure test done on the cooling system. This is where a air pump with gage is connected to radiator or overflow tank. Air is pumped into the cooling system and you can tell by the pressure gage if there are any leaks by a pressure drop on the gage.

If you have to take the head off, you might want to consider a valve job and new valve seals too.

P E H