Anybody had this issue or hear of this? I was on my way home from work on my 30 mile commute and I had to sit at a stop sign at a 4--way stop at the turnpike gate for about 5 minutes. I looked down and noticed my temp gauge was almost touching the red. My temp gauge never goes past the midway point. So, I knew something was wrong. The next morning I checked the radiator. Super low on fluid. I had to put the green stuff in there because that is all that was available at that time in my small town. Long story short, I traced it to a leaking heater control valve. When the new one comes in I will replace it and then flush out all the radiator fluid and replace with Toyota radiator fluid.