Boise Muffler Auto Repair is a full service automotive repair shop in Garden City, Idaho. For radiator and coolant replacements, come to us. We regularly maintain, repair, and improve our customer’s vehicles by utilizing our expertise of the automotive field, our customer service, and our values.
The radiator sits just behind the grill of your car and is the central hub of the coolant system. This system is responsible for maintaining and controlling the temperature of the engine. This is extremely important for proper function and performance from your engine, as well as overall engine health.
Coolant and antifreeze are the same thing. It is easy to mistake coolant for the liquid responsible for preventing the engine from overheating, and antifreeze for the liquid that keeps it from freezing in the winter, but they are actually the same thing. For simplicity’s sake, we will refer to it from here on out as coolant.
The reason coolant works for the prevention of both overheating and freezing is because it is made of, typically, a mixture of ethylene glycol (propylene glycol is sometimes used instead), water, and a few other additives. The combination has a higher boiling point and a lower freezing point than water. Water boils at 212℉ and freezes at 32℉. Most coolants boil at 256-260℉ and freeze at -36℉.
While water alone works as a coolant (and can be used in a pinch if you’re on the road and experience a break or leak in the system), and excels at heat carry off, it unfortunately forms rust on the iron engine parts. That rust is then carried throughout the system. It will affect heat transfer even before the build up and sediment it creates starts to plug the radiator and other components of the cooling system. Actual car coolant, on the other hand, has an extremely decreased risk of rust and corrosion.
Another reason water alone does not work as well is because of its freezing point. The expansion of ice causes cracks in the lines and builds pressure in the engine. Because there is already a risk of rust and corrosion in the cooling system, most of it is made of aluminum and plastic, plastic being susceptible to cracking from a water freeze. If straight water were used to maintain engine temperature, you would not be able to drive your car at 32℉ or lower.
Coolant leaves the radiator and is sent through the engine by a water pump. As the coolant passes, it transfers and carries off the heat generated by the burning of fuel and combustion happening inside the engine. The coolant, now hot, returns to the radiator where it is cooled down again before being pumped back through the engine.
The location of radiators in cars is a strategic one. As you drive, air comes in through the grill and hits the radiator positioned behind it, where coolant is spread through rows of thin metal fins. This method quickly and efficiently cools the temperature of the hot coolant. In addition, a thermostatically controlled fan positioned behind the radiator turns on to draw air through. This happens when the car is not moving fast enough for air to move through the radiator on its own.
Pressure is always present in the cooling system. This is because pressure allows the coolant to carry more heat without boiling than it normally would. The pressure in the system is controlled by the pressure cap.
Often, the same radiator and coolant system is used to cool the transmission as well. Transmissions create a lot of heat, specifically automatic transmissions. Sometimes there are two separate cooling systems for both the engine and the transmission, but it is more common to see them together as one system.
If you weren’t already aware, your coolant system is also responsible for heating the air in the cab. When needed, a spur line sends the hot coolant to the heater core instead of the radiator to cool off. The heater core is where warm air is generated to heat the interior on cold days.
The easiest way to get your answer is to check your vehicle’s user manual. Every car is different. Depending on the type of car and how you use it, you may need a specific type of coolant. Various mixtures assist with high mileage, high or low temperatures, rust and corrosion, and more.
Often, radiator and cooling systems should be serviced every 50,000 miles. However, some manufacturers recommend every 10,000 miles, and some even say 100,000 miles. As you can see, the frequency varies wildly, which is why you should always check your vehicle’s manual and consult with your mechanic.
Other ways to tell if it is time for a change is to check it yourself. Watch for low fluid levels, changes in color, and debris in the coolant. Most coolants are yellow or green. If it were to turn reddish, it likely means that you have a rust build up. This is why it is important for you to know what color it was when it went in.