I took the car in for the new radiator because it also needed new A/C condensor. The owner/mechanic said Nissens are junk and leak, he tried one on his wife's car. He doesn't like Behr much either, but believes they are worth it. Got the car back yesterday. 30F outside and the car runs 98C on the interstate. This is about the same as it was before the new radiator was installed. Around town it was running 80-90C mostly. Sitting at a stoplight long enough and the temp would drop to 80C. Climbing a long, winding hill at 45 then stopping to turn left and the temp gauge reads 100C and then cools down.

Before the new rad went in I ran a few types of flush thru the system and each one came out dirty. Prestone Super Radiator Flush + 100% water came out so dirty that I could not see thru it. I don't know if that's just a chemical reaction from marketing or it was actually doing something

I changed the t-stat in January, ordered from here (Wahler).

In the cold weather we are having, it seems that it works fine around town at but on the highway I think it should run about 90-95C even on long grades in this weather.

Any ideas as to what i should be looking for?

Brian