It is often the case that things may cause discomfort for people if they are not in their proper place. Air bubbles are one example. For kids, air bubbles blown away from soap liquid are pretty nice since they are beautiful to look at. But, for car owners, air bubbles are something they should be aware of. If there happens to be air bubbles in their engine cooling system, it may cause their cars to malfunction.

How most car engine cooling systems work

Most of the modern car cooling systems make use of the radiator coolant - which is a certain type of liquid - to keep the car temperature at a certain level. The heat produced by car ignition climbs up through cylinder walls and will then be absorbed by the radiator coolant. This coolant liquid or water is usually stored in a place known as the water jacket.

Having absorbed the heat, the coolant temperature will then climb up. The coolant circulation that takes place in the cooling system will then pass the coolant through the radiator fins. It is these fins that throw the heat away by moving it to the air. In order to optimize the cooling process, the radiator will need the help of the fans so that the release of the calories goes as expected.

In the cooling mechanism, it can be assumed that the radiator coolant plays a relatively important role. Hence, car owners must realise that this coolant is the main element that moves the heat from the place where it comes from to the place where it will be released.

However, there is often a problem in such a cooling mechanism. It is not rare to find out that there are air bubbles in the middle of the radiator coolant. This unexpected air will often disrupt the system pressure and eventually disrupt the coolant in its attempt of cooling the car engine.

Moreover, most of the modern cars have more precise gaps between their components. As a result, there is a greater chance of overheat in case something goes wrong in the engine cooling system.

How air may get in

Therefore, it is vital for car owners to understand how air may get into their engine. The most common cause is car owners attempting to open the radiator lid. This way, the empty space between the radiator coolant surface and the radiator lid becomes filled with the air. When the lid is closed, the air will be trapped inside the radiator.

The next factor that may cause air to get into the car engine is a worn out radiator lid. A radiator lid functions not only as a lid but also as a valve that moves the radiator coolant from the radiator to the reservoir tank when it is hot (when the pressure is high). It also moves the coolant from the reservoir tank to the radiator when it is cool (vacuum).

Yet, another thing that is very important as well is that the radiator lid is the one responsible for releasing the air trapped in the car engine cooling system. With that being said, if there is a problem with the radiator lid, it may lose its ability to release the air bubbles as expected.

This often happens as well to cars that do not have their radiator lid located at the highest level possible, causing some spaces to have a potential of trapping the air. This is one reason why car manufacturers provide a valve to throw the air away from the car engine cooling system.

This valve is often located at the top section of the car engine system. This is because car manufacturers realise that air moves vertically upwards. This is due to the difference between the pressure and the temperature in the car engine system.

How to get rid of the trapped air

Fortunately, there are ways by which car owners may get rid of trapped air. However, it is important for car owners to make sure that they make use of a disposal valve when they change the radiator coolant. This is to free the air bubbles from the car engine cooling system. Below are some steps to do it.

First, the car owners will have to make sure that their car engine is in a cool condition. Then, what the car owners will have to do is to open the radiator lid.

They will then need to switch on their car engine to allow the radiator coolant to circulate. While the car engine is working, the car owners will need to put in some water through the hole where the coolant enters the radiator. Needless to say, they will need to stop when the radiator is filled up.

Following that, the car owners will have to close the radiator. But, they will have to make sure that they close it perfectly to prevent air from getting in.

It is also necessary for car owners to open the air disposal valve. It is often located at the cylinder head near the radiator lapse, depending on the car make. The car owners may find this valve by reading through the car guide.


It is of utmost importance to pay attention to the coolant coming out of this valve. If bubbles are visible, there is still some air trapped in the middle of the way of the radiator coolant. Unfortunately, this also means that the car owners will have to perform the previous steps again until they cannot see bubbles coming out with the radiator coolant.

Last but not least, car owners will have to check the amount of the backup coolant. If the car owners happen to run short of this backup coolant, they will need to add more coolant until it reaches the maximum limit indicator.