Q: The thermostat in my car gets stuck closed and my car overheats. What causes this and how can I fix it?
A: A thermostat is a maintenance item that periodically needs replacing. The open and control mechanism can wear out. The thermostat consists of a spring, wax pellet, a piston, and other components that can fail. I would recommend having the thermostat replaced and the cooling system flushed. There could also be particles in the coolant affecting the operation of the thermostat. Make sure you replace the coolant mixture with 50% antifreeze and 50% water. A 50/50 mixture will give the coolant a freeze point of -34 degrees Fahrenheit and a boiling point of 226 degrees Fahrenheit.