What to know about your car air intake system

Thursday September 12 2019

In  some cars, external air is collected in the

In some cars, external air is collected in the mass airflow sensor . NET Photo 

By Roland D. Nasasira

When you talk of the car air intake, Immaculate Ninsiima and Michael Mugerwa who have both been motorists for the last two years understand it from the perspective of hot or cold air that is released from the air conditioner when they turn their ACs on.
Francis Mugenyi, a car air intake technician at Nissan Motorcare says your car air intake is quite different from the way your vehicle air conditioner works. Your vehicle air intake system runs on the intake, compression, power and the exhaust strokes, all of which make up the car air intake system.
In the intake stroke, is where external air that passes through the air cleaner is filtered before it goes into the intake manifold. In the intake or inlet manifold, fuel and air are mixed before the mixture goes to the combustion chamber for the power stroke to take place.
The intake stroke is where external air collects and then goes into the air cleaner. However, different cars have got different ports where external air is collected. In some cars, external air is collected in the mass airflow sensor that measures the amount of air that is supposed to be mixed with fuel.
After the mass air flow sensor has measured the amount of air to be mixed with fuel, it communicates to the Engine Control Unit (ECU), which also determines the right amount of fuel to be mixed with air from the airflow sensor to get the proper combustion. After this coordination and mixing, the mixture of fuel and air goes to the combustion chamber to get proper combustion.
“For petrol engines, as the air goes into the combustion chamber, the injector nozzle injects the fuel that mixes with air to the piston that further compresses the fuel to convert into mist form. The moment it mixes with air, the spark plug creates the spark that ignites the engine. You combine air and fuel and the spark to get the fire that is known as the combustion,” Mugenyi explains.

Factors that may affect the air system
In the car air system, the primary purpose of the air cleaner is to filter and clean air of any dirt before it gets into your engine.
In case your air cleaner is clogged, say with dust or any other kind of dirt, you will not get enough air to mix with fuel. If the air to fuel ratio is not as per the manufacturer’s specifications or when it is not equivalent to the engine, you will not get the right combustion.

Driving in dusty environments
Alex Kasozi, a motorist observes that some of the things that may clog your air cleaner include driving in a dusty road and you take long without servicing your vehicle. When your air cleaner accumulates dust and you do not remember to have it replaced, it will not serve you clean air. At most service stations or garages, the common mileage at which you should service your air cleaner and other parts is usually after covering or driving 5,000km or even less depending on the environment in which you drive.
However, in some cases, there is when you are supposed to just blow the air cleaner and other times when you ought to have it replaced.
If it is supposed to be changed and you insist and put it back in your after blowing, you will not get better air cleaner performance. In such a scenario, your air cleaner is either clogged or is due for replacement. There are also times when you find when grease or oils have gathered in the air cleaner, which is a rare case.

Damaged mass air flow sensor
When you insist on driving with an old or clogged air cleaner, you will subject your mass airflow sensor to fast wear and tear because it does not work with dust. If the air is not properly filtered, it will escape and go to the air flow sensor. As such, the car computer system will not be able to read the proper air to fuel mixture because it (computer) will not be getting the signal from the mass air flow sensor.
“You will experience a situation where your car consumes a lot of fuel. The computer will tend to compensate the lost air supply with fuel. You will also kill your spark plugs because fuel supply will be too much to the extent that the spark plugs will even fail to burn it,” Mugenyi warns.

Wet air cleaner
When you drive your car to a washing bay, it is likely that you will walk away and only return to pick it sparkling clean without inquiring to understand the kind of washing the attendant applied. Unfortunately, the washing bay attendant could have used a jet spray to clean around the engine compartment, something that Mugenyi cautions is not recommendable. They (bay attendant) will make a mistake and spray water into the air cleaner and when it absorbs water, it will fail to filter the air, thereby exposing the air system to dirty air.

Cost of servicing a car air system
On average, if you are to service your car air intake system, which involves replacing the air cleaner, mass air flow sensor and the injector nozzles, you will need to spend approximately Shs3m depending on the type of the car. Yet if you had serviced your car at the prescribed period, you would spend Shs500,000.
The air cleaner should only be blown when you have covered between 5,000 to 10,000kilometers. If you spend more time on a murrum road, it is advisable to blow your air cleaner before covering 5,000km because of periodic exposure to dust.