Coolants

The internal combustion engine builds up heat as it runs. The small explosions that take place inside the cylinders as well as the friction creates this heat. Engine oil, helps avoid some heat generated by the engine friction, along with some reduction due to air flowing over and around the engine. However, this is not enough to keep the engine from overheating and creating damage to its parts. There have been some successful air-cooled motors such as those in motor bikes and of course the Volkswagens such as the beetle and combo. But removing excess engine heat from the traditional four stroke internal engine requires ‘water cooling’ jacket around the cylinders. Or more precisely a water / coolant mix. When the car is running it is the job of the circulating coolant to dispense with this excess heat as it passes through the radiator. The radiator of course also has a fan that will run to keep the air flow over the radiator especially during times where the car is not moving or moving too slowly to create its own airflow.

How long would an engine run without coolant? Not very long in most cases. Perhaps minutes. The heat generated is quite incredible. If the motor is run for long without coolant it is generally severely damaged even if it does not completely heat seize. From my observations damage to most motors requiring the motor to be rebuilt or replaced is caused by either faulty poorly maintained cooling systems or a lack of coolant or both at some point.

Why Do I Need Coolant…? Why Not Just Use Water?

Well water alone could work, but a few of extra things that coolant does are as follows:

  1. Provides resistance to corrosion in the engine cooling systems by avoiding things like electrolysis
  2. Dissipate more heat than water alone can and avoids the system boiling at higher temperatures
  3. Stops freezing of the coolant in extremely low temperatures

These are two pretty important factors to consider when you choose a coolant for your vehicle.  Normal or even distilled water will allow metallic parts and even rubber or even synthetic parts to perish and corrode more quickly.  A quality coolant is critical in avoiding these reaction.  The reactions are magnified at higher temperatures and under pressure.  The ratio of coolant to water you use and the coolant quality will make sure that the life of the cooling components will be at their maximum.  It will also make sure that under load your engine has the best possible chance of transferring all that heat to the air.  So let’s say you develop a cooling system leak and you are topping up with water regularly.  You need to remember that you will be diluting the effectiveness of the coolant.  This can have catastrophic affects.  The moral of this story is get the leaks fixed immediately, flush, clean and replace the coolant as quickly as possible!

Composition and Importance

Coolants are usually a mix of water and various chemicals. One of the often used chemicals is propylene glycol.  It is a chemical additive that lowers the freezing point of the coolant. It can often be referred to as antifreeze.  Although there may be other additives in the coolant such as glycerol that helps enhance this affect.   Glycol also helps in raising the boiling point of water thus making the engine temperature stable in very hot climate or if the engine is subjected to extreme conditions. A good ratio is to mix water and antifreeze 50/50. This is sufficient enough for the kinds of conditions the engine is subjected to. However, it is also good to note to check the specified ratio by the car manufacturer in the car’s user’s manual.   If you are in an cold climate or at that part of the year where freezing of coolant could be an issue.  You must make sure that you are using a good antifreeze rated coolant and it is at the right ratio.  Otherwise your motor can be severely damaged.  It is possible for the freezing coolant to crack the block of your engine!  So keep the ratios right for your area.

Without the coolant, the engine can overheat leading to mechanical failure and a costly repair/replacement of the engine. Water, although a very good coolant by itself, is not enough to provide sufficient cooling for the engine. The reason being is that water has a low boiling point. Adding glycol can raise the boiling point of the coolant and can help the engine operate efficiently at high temperatures.

It is vital to check the coolant level often to prevent possible overheating or hot spots in the engine. Although the main component does not break down, some of the inhibitors present that prevents corrosion eventually do.  Once the the inhibitors are used up, corrosion starts to eat away at the metal inside the engine and radiator. The images below show corrosion due to the coolant-inhibitors being used up.

Corrosion Due to Coolant-Inhibitors being used up

How To Change Your Vehicle’s Coolant

Given the importance of the cooling system in the optimum performance of your vehicle, it is critical to check it often and change when necessary. Also take note of the car’s users manual specification on when to change the coolant. There can be reasons and benefits to change the coolant sooner than specified by the car manufacturer. Personally I check the cooling system as often as I can for signs of corrosion and proper level etc. This is one maintenance habit that practice to help me get me more miles out of my engine.

Note* Follow your car’s users manual instructions for draining the spent coolant from the cooling system. The steps below are some of the things I usually do when changing the coolant in my car. The steps listed here may or may not apply to your vehicle and should be performed with utmost care if ever you decide to follow the steps shown here.

  1. Park the vehicle in a safe place, away from children and animals. Waste coolant is dangerous to animals or children and can be fatal to them when ingested.
  2. Make sure the engine has cooled down and ignition turned off before changing the coolant. This is to prevent harm to you. Also be aware that the system is under pressure.  So use a rag and release the pressure in the system gradually and carefully.
  3. Gather all the necessary tools, like screwdrivers, draining pans, needed before starting on the coolant change. This will save you time and make the change faster. Also make sure to use the coolant/antifreeze specified on your car’s users manual to prevent unwanted damage due to using of unspecified coolant. Do not compromise on low quality or low ratios of the coolant.  It can be a costly mistake if you end up with corrosion or over-heating.
  4. Using the owner’s manual, check and locate the radiator drain plug.  Place the drain pan or receptacle below the drain plug, hose or tap. Loosen the screw plug, bolt plug or in many cases there is a simple drain plug (petcock). Avoid spilling the drained coolant onto the ground or into storm drains or sewers to avoid pollution of the environment.
  5. Once the liquid has completely drained, close the valve and pour the used coolant into containers with tight-fitting lids. I make sure to label these containers and store them away in a safe place like a cabinet with a lock in place. This will ensure the safety of our pets and our children who are not aware of the dangers of being exposed to such items. When disposing of the coolant make sure it goes into a the right drums at your local municipal tip.  There are usually drums available for these sort of wastes if you ask the attendant.
  6. The next step would be to flush the radiator using water and a radiator flush solution. Close the valve, open the radiator cap and pour the radiator flush solution. After that, you should run the engine with the heater control on High for about 10 minutes.  This ensures the flush compound will circulate into the heater core. Make sure to watch the temperature gauge or warning light to avoid overheating the engine. Allow the engine to cool off before attempting to drain the water or flush solution to prevent burns or injury to yourself. Once the radiator is cool enough to touch, drain the flush solution and transfer the drained liquid to tight-lid containers and make sure to label the containers properly to avoid accidents.
  7. After all the liquid has drained, close the drain plug and begin adding the new coolant mixture. However, before adding the new coolant, make sure that the one you are using is specified by the car manufacturer. Also take note on how much coolant your cooling system can hold. These are pretty simple steps that are often missed or taken for granted, but the result can be very expensive. Make sure that the liquid reaches the proper level on the coolant reservoir and continue adding if it doesn’t.
  8. Replace the pressure cap and run the engine with the heater on High until the temperature meter reads in the normal range. Double check the levels and finalise the top-up.  This is an important step as there are often a few air locks that only come out once the engine is run up to temperature and the thermostat opens.  Do not miss this step!
  9. Clean up. Make sure to put contaminated rags in sealable plastic bags and put them into garbage. And again, make sure to place unused coolants away from your kids or pets by storing them in a place where the coolants could not be easily reached.
  10. Also I make sure to check the liquid level after a few days of driving the car. This is to make sure that the cooling system has enough liquid to cool the engine when the car is running. If it is low, then just add until it is on the right level.
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