Coolant is a liquid that lubricates your engine and protects it from corrosion. It is usually mixed 50/50 with water which is a better conductor of heat than coolant. The coolant raises the boiling point of water which allows the cooling system to be more pressurized and work more efficiently. Your engine is really a contained explosion device, that powers your car. The series of explosions heats up the engine and can eventually warp the metals inside if it gets too hot. The coolant therefore is very important to ensure your engine does not overheat or rust, and on top of that it also protects the engine from being damaged by the intense friction.
What Coolant Does
The coolant mixture is pumped around the engine by a water pump. The coolant passes through the engine, absorbing heat, and takes it to the radiator. From there, the fins of the radiator allow a lot of air to flow through the engine compartment which cools the coolant down. At lower speeds or idling, a radiator fan is usually active to assist the airflow into the engine compartment. The cooled solution is then sent circulating around the system again. A thermostat will regulate the flow of coolant to keep the engine at an optimum temperature (200℉, 95℃). When the car starts the thermostat will block the flow of coolant to allow the engine to heat up.
Why coolant is important
The heat inside the engine is enough to warp the internal metals. Aside from being functional, the engine also needs to be efficient, which is why there is an optimum temperature. Water alone would boil quickly and evaporate to leave a cooling system full of hot moist air, something that would cause corrosion. The coolant mixture prevents this by having anti-corrosion properties and raising the boiling point of water. The pressure cap on the radiator also helps to maintain the water as a liquid by holding the system at a specific temperature. In cold weather, the coolant also prevents the water from freezing by lowering the melting point.
The coolant will need to be replaced eventually, as while the antifreeze doesn’t expire, the corrosion inhibitors do. Usually, this will be done during your scheduled services. The cooling system needs to be flushed then new coolant will be added. Multiple types of coolant may react badly together and clump together, clogging the system for an expensive repair.
A scheduled service can check the rest of the cooling system for any other issues. A lot of repairs for overheating can be solved by making sure your engine is working well. Ensuring your engine’s cooling system is working just before the summer heat can save you thousands in repair bills.