All About Car Exhaust System
The car exhaust system is responsible for removing the burnt air-fuel mixture from the engine. However, that’s not its only purpose. Various components in the exhaust system work together to reduce emission and noise generation. A bad exhaust system will not only reduce the engine’s efficiency but might also get you fined for excessive noise and pollution in the UAE.
This guide will help you understand how car exhaust system works and how you can make sure that it’s working properly.
How Car Exhaust System Works
The exhaust system is connected to the main engine through a series of pipes and essential components. In most vehicles, the exhaust system has similar components that allow the exhaust gases from internal combustion engines to escape.
The core function of each component is to direct the exhaust gases while reducing the emission and muffling the sound. Let’s take a look at each component:
During the exhaust stroke in the internal combustion engine, the gases and sound waves are directed towards the exhaust manifold via the exhaust valve. The gas and sound collected here are then forwarded to the catalytic converter.
A car engine emits various harmful gases, including carbon dioxide, carbon monoxide, nitrogen oxides and sulphur oxides. Sometimes the composition also includes unburnt fuel and particulates that can lead to major health issues.
The catalytic converter acts as a barrier by converting harmful gases. The converter makes use of platinum, rhodium and palladium to reduce or oxidise harmful exhaust gases into less hazardous gases. For instance, harmful nitrogen dioxide goes under a reduction process to release nitrogen and oxygen. Similarly, the poisonous carbon monoxide goes under oxidation to produce non-poisonous carbon dioxide.
Modern catalytic converters also have oxygen sensors to control the amount of oxygen for an efficient reaction.
The exhaust gases become less toxic and harmful due to catalytic converters. However, the generated sound waves remain in the system. This is where the resonator and muffler come into play. The key difference between the two is of functionality. The resonators tend to cancel some sound frequencies, whereas mufflers reduce a wider range of sounds. Hence, resonators are not usually found in all cars.
The resonator is usually placed before the muffler. When the sound waves hit the resonator walls, it bounces back with the same frequency. The bounced waves cancel out the upcoming waves. This helps eliminate some ranges of sound.
The muffler reduces the sound to a more pleasant level. The muffler consists of multiple chambers with perforated pipes to allow gas expansion in the chambers. The expansion of gases causes reduction in gas pressure, which ultimately reduces the sound level. Before gases leave the muffler, they are rerouted in the muffler to further reduce the noise.
The tail pipe directs the gases from the muffler to exit into air. The pipe usually extends past the lower rear end of the vehicles. Tail pipes backends in modern cars are often customised with chrome finishes and unique design features to make the car look sportier and athletic.
SIGNS OF A FAILING EXHAUST SYSTEM
The efficiency of a car engine is partly dependent on the exhaust system, as it affects the overall vehicle performance, fuel efficiency and sound generation of the vehicle. If you witness the following signs, a damaged or failing exhaust system could be one of the culprits.
Loud Exhaust Noise
Loud exhaust noise generally means a problem with muffler, tail pipes or the exhaust manifold. Damaged components or cracks in the pipe system can lead to loud sounds and increase the risk of getting fined by the traffic police. For instance, driving a noisy car in the UAE can get you fined AED 2000 with 12 black points.
If you smell gas odour, it’s likely the catalytic converter has stopped working or there is a leak in the pipes before the converter. As these gases get seeped into the cabin, you are exposed to harmful and dangerous gases. This can also cause water to leak from the exhaust.
Low Fuel Economy
Although there are various reasons that can affect the fuel economy of the car, a blocked or obstructed exhaust system can be one of the reasons. Blockage in the exhaust system will cause your car’s engine to work more while reducing the overall fuel economy.
Lower Engine Efficiency
The engine power is dependent on the back pressure of the exhaust system. Less pressure means more gases can leave the system easily. Clogged components like catalytic converters, can significantly reduce engine power. It can also result in car exhaust backfiring.
It is common for an exhaust system to accumulate rust and corrosion. The components go under a regular cycle of heating and cooling. The presence of water vapours released from exhaust itself can gradually lead to corrosion. Too much corrosion can break parts or cause leakage in the affected areas.
A damaged exhaust system hampers the engine performance. Hence, it is important to get it checked immediately as a defective exhaust system can be dangerous to health and is subject to fines in the UAE.
Modern cars nowadays are often equipped with dual exhaust systems. This does increase overall performance as the engine is able to push used up air faster. However, dual exhaust works best with bigger cylinder engines like V-6 and V-8.
If your car makes too much noise or regularly requires maintenance work, you are better off replacing it with one with a better exhaust system and lower emission. Check out these affordable used cars for sale in Dubai for reasonable options.
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