I have two 1990 Cougars non-supercharged, and one had a dying engine, so I took the engine out of the other one. (The other one had a dying transmission so it was a perfect match, I guess.) After the engine swap I found someone had filled the cooling system and engine with Bars-leak and pepper. So I bought some radiator flush and flushed the system after replacing the radiator, all cooling system hoses, thermostat, water pump, and temp sensor. I then had a leaky radiator, so it was replaced under warranty. With the new radiator installed, I once again flushed and burped the system. The car continued to overheat, so I did some investigation. The impaler on the water pump was failing, so I had that replaced under warranty, also. Two water pumps, two radiators, and six thermostats later, how do I continue to overheat? I haven't replaced the temp sensor, except for that one time, so should I do that? Also, could this be an electrical problem instead of a mechanical one? Should I buy parts somewhere else? This is the first car AutoZone has disappointed me one.