I bought my Saab a little less then a year ago knowing I had a very small oil leak. Its been leaking oil really bad lately so I figured it was just a leaky valve cover gasket. Well to my suprise I found a big crack on the backside of cylinder head....OUCH! I do remember the seller of the car having the water pump and thermostat replaced before I purchased the car. I'm guessing it overheated and that caused the head to crack. Also my car is using anti-freeze, but its not leaking. At this point, would it be best to replace the cylinder head or is there further damage to the engine? It runs great now, doesn't burn oil or have a funny color to exhaust.