Could very likely be headgasket, get it checked.
Wouldn't the oil be creamy if it was the head gasket?
How can you check? Will there be any Obvious Sign's to check??
Nope, not always. Why do people always say this?
How can you check? Will there be any Obvious Sign's to check??
Yes, some symptoms are.....coolant loss, but not external leaks. Take it for a good drive, then check to see if any coolant hoses are rock hard.
Power loss due to lack of compression in one cylinder thats letting the coolant steam off.
Some cases air locks and over heating, but depends how big the gasket split is.