When I hear the word "overheating" I always wonder just how hot did it get. Did someone continue to drive the car once it indicated it was overheating? With aluminum engines they only have to "overheat" once for a few seconds and serious engine damage can often result.The only real fix then is to start taking the engine apart and this will not be cheap and can sometimes cost more than the car is worth.
Well the final diagnoses is a cracked head between the exhaust port and the water jacket on the rear head. However it does not leak until after the engine reaches operating temperature. Usually after running for about 30 min. There were apologies for the initial diagnoses and no charge for the unwarranted repairs. They are now reviewing the repair options. Either replace the head and all the associated work that goes with it. Or replace the engine. The second option gets Mom a 3 year 100K mile warranty on the replacement engine.