So I did a test I saw done on youtube where you remove the coolant tank cap and run the car til it gets to operating temp. Once the thermostat opens, if the head gasket is blown, they say it will cause the crankcase pressure to go into the cooling system causing it to bubble out as if it was over heating. (See video) I did this and had those results. The coolant overflowed and bubbled like crazy even though it wasnt hot enough to be overheating. I am moving in a couple weeks so I havent torn the car apart yet to check the oil cooler. But Im thinkin head gasket.