Lately the subject warning light takes a very long time to go out after a cold engine start up. The car has not lost any significant amount of coolant and level is exactly where it should be, and was previous to this problem developing. Eventually the light will go out and stay out until the car cools off overnight. Im suspecting that the sensor for the light is some sort of conductivity probe that senses a change in resistance from low when wetted to high when the coolant level drops below the sensor electrodes. In my case, I suspect that there might be some sort of fouling on the sensor that keeps the resistance high even when the sensor is covered by coolant. Where is it, on the bottom of the overflow tank? Anyone else encounter this problem?
The change in overflow tank level from a cold engine to a normal temp one is totally normal and both levels are above any sensor that might be in the tank. Again, have not lost nor needed to add any significant amount of coolant. I did put a small amount in to bring the overall levels up a bit and no change in the sluggish response.
