The 2001 Pontiac Sunfire lost the convertible option of previous years and offered only sedan and coupe options. It was produced from a similar design of the Chevrolet Cavalier, another General Motors model. The Sunfire has traditionally been Pontiac's lowest-priced offering and was intended as a low-hassle vehicle. The SE model has a 115-horsepower, 2.2-liter engine with four cylinders. Changing the radiator coolant on the Sunfire is a time-consuming process, but you can save some money if you do it yourself rather than taking the car to the shop.
Park your Sunfire in a safe area where you have room to work, and where pets and children will not have access to the vehicle. Coolant has a sweet smell that can attract kids and animals, but it is extremely toxic. Turn off the car and let the engine cool off.
Open the drain valve in your radiator and let the coolant pour out from the engine into a drainage bucket. A 2-gallon bucket should be large enough to accommodate the coolant.
Close the valve and fill the radiator with a mixture of water and an engine flush. The flush directions should tell you how much water needs to be mixed with it. This is designed to clean the radiator and coolant system before you add new fluid.
Start the car and run your engine at normal idle with the heater on high for about 10 minutes. Turn the engine off and drain the flush mixture into your drainage bucket as you did earlier. Once the engine is cool, fill the radiator with water.
Turn on the car again and run the engine for another 15 minutes at normal idle. Then turn off the car and drain the water from the radiator drain valve.
Add new coolant to fill the radiator. You may need to add water as well, depending on whether your coolant is premixed. Follow the instructions on the back of your coolant container.
Start the Sunfire and run the engine at normal idle with the heater on high for 15 minutes to circulate the new coolant throughout the engine.
