I just recently bought a 1996 Oldsmobile Aurora. The day I got the car, the in dash computer was showing (change oil now). I drove the car constantly for about 4 hours, here and there. Then the computer displayed (low engine coolant). So my friend went in and bought the green prestone coolant. After he added it, we went to get the oil changed. They only added 5 quarts. Within 20 minutes of leaving the shop, the car overheated and I had to turn it off. After letting it cool, I was able to drive it a short distance to my house. Since then I have learned that you are only to add the orange dex-cool coolant. I have flushed the system, replaced the thermostat, changed the water pump. However the car still overheats within 15 minutes of starting it. When it gets hot it blows all of the coolant out the overflow cap. I was told that is sounded like a bad or cracked head gasket. When I called the dealer they told me that Auroras do not have head gaskets go bad, and that I need a brand new engine. Has anyone else had this problem or does anyone have any suggestions. Also I found a product on the web called thermaweld, it is supposed to fix this type of problem for $300.00. Has anyone tried this. Or do you think that it is a bad idea.