Still working on my overheating problem with '96 Sable. The water pump was replaced, and thermostat. (BTW, infrared indicated overheating was occuring.) That didn't seem to help. Just for the heck of it, the mechanic used Bar's header plug stuff. Since then, the issue is better. It would help me if I knew what was normal for a 96 Sable LS (3.0 Duratec.) In 90 degrees with air conditioner on. the temp guage is rising to about 3/4 up the gauge in stop/go surface street traffic instead of going to the top. Is running at 3/4 in those conditions normal for this engine?

I have a 97 with sohc and I did all the things you did. To solve my heating problem I had to get the radiator boiled out twice. Have the radiator shop do this because the radiator has to be removed form the bottom. This is a closed system and the circulation goes through the expansion tank so keep the tank full. Hope this helps