pt cruiser with oil in radiator and no water in oil is the oil cooler bad?

[Jay]

I have oil in my radiator, and no water in the oil- the pt cruiser has an oil cooler- not sure where? but the car still runs like nothing is wrong and there is no smoke either .. someone immediately told me that it was a blown head gasket (think he was jsut trying to charge me more)and I am sure that is not it ! please help ?