Q: difficulty factor replacing thermostat and censor for a 2012 Chrysler 200. do I need to drain the radiator

Hello there, thank you for asking about your 2012 Chrysler 200. As long as you reduce the coolant level below the area you will be working in, you don’t have to completely drain the coolant. However, be sure not to drop dirt or debris in the coolant. When you add coolant back, be sure you open any air purge points on the cooling system, if your car is so equipped. Otherwise air could get trapped and it is possible to have an overheating condition due to trapped air. The air purge points on the cooling system are identified in the factory service manual. If you have been led to these components because of difficulty with your car, just be sure you are not needlessly replacing them. Your car does not have high miles and those components should last 100,000 miles or more. I am not sure which sensor you are referring to but many sensors will outlast the car itself. If you need a diagnosis or second opinion, a mobile technician from YourMechanic can come to your home or office to help you replace your car’s thermostat.