Owning a car means becoming familiar with several essential components of a vehicle. One such component is the coolant which is crucial to the functioning of the engine. While coolants may come in different colors, car owners may find them becoming brown after some time. This article focuses on why coolant may become brown and what to do if that happens.
The main reason why coolant becomes rusty brown is corrosion. As coolants age, they lose some of their protective properties and become prone to corrosion and degradation.
Water is not enough to cool car engines. You need a coolant to lower the temperatures of the engine to improve engine performance and lifespan. Whether you are familiar with coolants or never heard of them, you are about to learn all you need to know about car coolants below. So, keep reading.
What Is A Car Coolant?
A car coolant, also called antifreeze, cools a car’s engine, as its name implies. As you may already know, your car’s engine is powered by the combustion of fuel and air. Part of the energy generated from this combustion is used to power the engine, while the rest is converted to heat. And while some of the heat is released from the engine through the exhaust, the rest remains trapped in the engine.
All engines have an operating temperature range. Excess heat in the engine will lead to temperatures that exceed this range, and this increases the stress on engines, thereby increasing the likelihood of engine failure.
A coolant is specifically designed to lower the heat generated in the engine and keep the temperature within the optimal range. Coolants are usually made of water and ethylene glycol or propylene glycol. They may be pink, blue, green, or even red in appearance, depending on their composition.
How Does A Coolant Work?
Coolants are introduced to the engine through a reservoir connected to the radiator. The cooling system disperses the coolant through passages in the engine block and heads. As the coolant passes through these passages, it absorbs excess heat generated by the engine. After absorbing the heat, the coolant itself becomes heated and is eventually cooled by an air stream entering the engine compartment through the grill in front of your vehicle.
Why May Coolants Change Color And Become Brown?
As mentioned earlier, coolants come in varying colors depending on their composition. However, they never come in brown. When your coolant becomes brown, it’s a sign that the coolant is no longer in good condition. There are a couple of reasons why coolants may change their colors to brown, and the reasons are discussed below.
Additives Dropping Out
A typical coolant is made of ethylene glycol or propylene glycol, water, and additives. The base (ethylene glycol or propylene glycol) is responsible for the primary cooling action of coolants, while additives are designed to prevent corrosion, scaling, and cavitation. And the additives may come out or be separated from the coolant solution over time. When this happens, the coolant goes bad and becomes rusty brown.
Mixing incompatible coolants can also lead to additives dropping out of the solution and the coolant going bad.
Contaminated Coolant
Coolants are not supposed to come in contact with other fluids. But sometimes, coolants can mix with oil due to a bad head gasket or cracked cylinder head. It’s also possible for coolants to come in contact with transmission fluid if there’s a breach in the engine cooling system.
When a coolant comes in contact with oil or transmission fluid, it goes bad as it loses its cooling properties. Eventually, the coolant will change color and become brown.
Corrosion
This is the most common reason for coolant becoming rusty brown. As mentioned earlier, coolants contain additives that are supposed to protect them from corrosion and degradation. However, these additives will degrade over time, and when this happens, the coolant becomes susceptible to corrosion, and a corroded coolant is a rusty brown in color.
What To Do If Coolant Becomes Rusty Brown?
Most times, coolants become rusty brown from age. So, when you notice your coolant has become brown, it’s time for a new coolant. Check the owner’s manual for the type of coolant your car uses and the recommended interval for changing coolant. If it’s past the recommended interval, you have to change your coolant.
However, if you notice your coolant becoming rusty brown before the recommended interval, check if you are buying the correct coolant. If you have bought the correct coolant and the problem repeats, you should consider having a mechanic inspect your car to check if the coolant is mixing with engine oil or transmission fluid.
How To Change A Car Coolant?
Changing a car’s coolant is easy if you are handy with tools. Below, you’ll find steps on how to change a car coolant:
Park The Car On A Level Surface
You’ll have to jack your car up to drain the coolant. So, it’s important you park on a level surface before you get started. Ideally, you should park on a concrete or blacktop surface, as gravel or dirt may not provide enough support for your jack. You can also use your garage if you have one.
Jack The Car Up And Locate The Drain Valve On The Radiator
Unless there’s enough space under your car to accommodate a bucket, you’ll have to jack the car up. Remember to use jack stands to take some of the weight off the jack and to better support your vehicle.
Locate the drain valve of your vehicle and open it. If you can’t find the drain valve, consult the owner’s manual. Place a bucket under the valve before you open it. After the coolant stop coming from the valve, close it tightly.
Fill The Radiator With Water
To completely get rid of all the coolant in the engine, pour a jug of water into the coolant reservoir and start the engine. Turn the heat on to the maximum and let the engine run for about 10 minutes. Then, open the drain valve to collect the remaining coolant, which is mixed with water.
Add The New Coolant
Allow your engine to cool before adding new coolant. While you may have run the engine for about 10 minutes, it will take longer than that for the engine to cool. Check the owner’s manual for the type of coolant to use. Most vehicles require coolants to be mixed with water 50/50.
Pour the new coolant into the same open cap you poured water on earlier. Some vehicles may have special instructions about how to add coolant, so be sure to consult the owner’s manual.
Start The Engine
After adding the proper amount of coolant, close the cap. Check if there is any leakage, especially around the drain valve. If there’s leakage, try to close the drain valve properly. You may also need to replace the drain valve if it doesn’t close properly. And you are all set to enjoy your new coolant and the benefits it offers your engine.
Remember to dispose of used coolant properly. Auto shops can help dispose of old coolant for free or for a small fee. Used coolant is dangerous to the environment, and it must be disposed of in the right way.
