Hmmm…. I’ve been watching an issue unfold for about the last 2 weeks on my car. Because it’s been sooooo cold here (I only drive it on dry roads), I watch my temperature gauge religiously. I’ve noticed the car go to 209….which it’s never done in 90 degrees, let alone in 0 degrees F. So the other day I started it at work and it got to 40….I sat there for another 2 minutes idling and it didn’t move. Then it suddenly shot up to 65. Another time it got to 145 and stayed there for several minutes of driving before it started to move again. I’m concerned at this behavior. It’s never done these things before which is concerning…. I know that it is most likely a thermostat….but another engineer suggested a head gasket. I know that it’s been running rough, but that’s nothing new and is caused by my current crappy tune. Just wondering what everyone’s thoughts maybe on this…… I’m going to look at coolant and oil tonight when I get home….