Changing your engine coolant is just as important to life of your vehicle as changing your engine oil is. Bad coolant can lead to overheating and can cause head gasket failure and other costly repairs. Another factor can be living in areas that experience colder than average winter temperatures that can cause your bad coolant to freeze. Luckily it is easy to change your own coolant at home. All you need is common household tools and containers to hold the old fluid. you will need a screwdriver (flat head), a set of wrenches, and containers to expose of the old fluid.