yesterday. The needle used to only rise when the A/C was on. Yesterday it started to rise when I went on the highway (200 mile trip, had to think of something). I set the A/C, which also turns the heater on for a bit, temp gauge shot right back down to normal for a little bit longer. Problem ended up being a corroded temp sensor for the ECU.
Funny thing is my girlfriend says I'm too fast. Go figure ~jonnyz (DC)