. i dont remember the last time i filled it up, but i do know there is a low-coolant light by the gauges, and i thought that would alert me when the coolant got low. well, i pulled the overflow container, and found that the sensor plug at the bottom of it wasnt plugged in all the way. i checked the overflow bottle for leaks, then put it back in the car and filled it to spec. then i checked under the radiator cap, and there was plenty of coolant there. if it helps, i checked the oil for coolant, and coolant for oil with the idea in mind that maybe a bad head gasket is at fault for emptying all the coolant, but both oil and coolant were clean. could i have done any damage by running without any fluid in the overflow container? i dont know how long i was driving with it empty, but the temp gauge never got above the middle mark. ideas?