This is a room for information for automobile problems. If you have a auto problem, please post. If you know a solution to a posted auto problem, please post. If you found a solution that is common/uncommon knowledge to a posted auto problem, please post. My first problem: Car overheating. Mercury Grand Marquis 1996. Bought both temp sensors, thermostat, coolant flushed, new reservoir cap, checked all hoses. 2nd problem same as first, still overheated. checked oil for milky substance-none checked if radiator leaking-none left reservoir cap off and ran car, it bubbled head gasket problem-none ran car 3rd problem same as 2nd and 1st. overheated solution: took out thermostat cons of taking out thermostat: less mileage efficiency no heater (until car warms up) open coolant system pros: wont overheat again ran car to work today: didn't overheat, didn't even come close. Uncommon knowledge: gutted the innards of faulty thermostat (bought two of same brand and maker, both faulty). installed the thermo-cap back into the housing making it have some resistance. car is 1/4 to 1/2 temperature, had heat from heater. the real fuel efficiency problem is that gas prices are not fuel efficient.