Your cooling system’s job is to keep your engine cool. Coolant (also called antifreeze) mixed with water flows through your engine and absorbs heat. The mixture then flows out to the radiator where it’s cooled by air flowing over the radiator. From there the cooled mix circulates back through the engine to absorb more heat.
Coolant, or antifreeze, is specially formulated to keep your engine safe in a wide range of environmental and operating temperatures.
Without coolant, the metal engine parts would expand so much that the engine would seize up and stop running. Expensive parts could be broken or warp so badly they would have to be replaced. It could even be so bad that the whole engine is ruined and has to be replaced.
Also, if it’s freezing outside, the water in your engine could freeze while your vehicle is sitting out in the cold.
Therefore, check coolant levels frequently and have your cooling system inspected for leaks. Also, your manufacturer has a maintenance requirement for draining and replacing your coolant. These recommendations can vary widely, so check your owner’s manual or ask your service advisor.
The reason you need to change the coolant is that it has additives in it to protect the cooling system. As you can imagine, with all the heat, the cooling system’s a pretty harsh environment. The additives keep the fluid from becoming corrosive and damaging the radiator and other cooling system components. Over time, the additives are depleted, and the coolant just has to be replaced. A simple Ph test can measure the coolant’s acidity.
You may have noticed that there are different colors of antifreeze: it is very important that you use the correct type. The different coolant types are different colors, so you don’t mix them up. Manufacturers use different materials to make the cooling system, and they require different types of antifreeze to protect them.
So, check with your service advisor or owner’s manual for the right kind because using the wrong coolant can void the warranty for your cooling system.