Since I bought the car my indicated temp has struggled to reach past 70 no matter what the conditions and the heating inside the car is best described as luke-warm at best.... but today I went house hunting, and as I stopped to sak for directions and re-adjust my GPS I noticed the temp guage was off the scale and the red light was on... I pulled over and had the nice sight of steam pluming from the coolant reservoir whilst my coolant bubbled like a kettle. I slowly released the pressure, checked for burst pipes and waited for the engine to cool down. I noticed that the rad fan had not kicked in, is this a result of the 'stat going south as I suspect, or is it possibly something more?