Radiator started to leak from overflow hose and would cause an overheat. Tried several fixes, but the leak returned while driving after a day or so. Now finding coolant in oil and oil in coolant and coolant leaks from what looks like where the head meets the engine block, but could be around freeze plugs. Can't really tell for sure. I have the foam on top of the oil and under the oil cap and pools of oil in the coolant refill tank. Car still runs, but I only start it up every now and then to be sure it's doesn't lock up. When I start it up I have white smoke from the exhaust for a while then it starts to stop smoking. I assume it is either a blown head gasket, warped head or cracked block. Are there any other things I can look at myself to help determine the issue without taking it apart as i have no tools. What is the most likely problem and what kind of cost am I looking at?