Ever since I got my car back from a complete rebuild it has been running about 15 to 20 degrees hotter than nornal. It doesn't matter if it's 75 degrees in the morning or 95 degrees in the afternoon. It still runs around 203 on the highway. Could the thermostat be not opening all the way or maybe an air bubble or what? Runs the same temperature with or without the air on. It does have a 165 thermostat. Thanks, R.B.