I have a 2002 Subaru limited Outback with 99,000 miles on it. I went out to warm the car and turned the heater to low and let it sit 10 minutes. Took off to take Daughter to work and got halfway there and noticed that the car temp gauge went up significantly and there was a smell of gas and oil inside the car. I turned the heater off and the temp gauge dropped down back to where it normally stays. At the stop light I still had the heater temp on red (hot) from when the heater was on and could feel really hot air still coming from the vents and the gauge when up again. When I switched that to knob to cold it went back down. Ran fine and gauge was normal till the next light. It didn't go to where the needle had been going but it did jump up a little bit at idle. Anyone know what I could be dealing with here? And what can be done?