A complete guide to your car’s exhaust system: How does it affect the MOT?

Have you ever found yourself in a traffic jam where the car in front of you has been emitting black smoke, vibrating constantly, and producing rattling sounds? In such situations, most car owners think of a broken exhaust system. If you do, then you have an initial knowledge of a vehicle’s exhaust system and its workings. However, a basic insight will not help you prevent exhaust damage to your vehicle. To do that, you need to recognise its various components and their functions. Find out in this guide detailed insight into the exhaust system and how it affects the MOT Cheadle.
 

What is an exhaust system?

An exhaust system is an integral component of your vehicle, including various vital parts serving their specific functions. A properly functioning exhaust system is just as important as the engine of your vehicle, contributing to a smoother driving experience. The most critical function of your vehicle’s exhaust is protecting the cabin from harmful emissions from the engine. This system is also important for reducing the level of noise and vibration produced by a vehicle. Hence, an exhaust system is a highly crucial component for your car’s smooth functioning and performance.

What is the basic structure of an exhaust system?

The exhaust system is not just a whole one-part component. It comprises five smaller parts, each of them serving their functions.

These include:

Exhaust Manifold: It is usually the part where the exhaust system starts. The manifold connects the engine with other parts of the exhaust system, with tubes emerging and entering it. The purpose of the exhaust manifold is to collect the exhaust gases from engine cylinders. It directs these harmful gases to the remaining components and ensures they do not go back inside the vehicle.

Oxygen Sensors: They are found on either side of the catalytic converter. As the name suggests, oxygen sensors are vital for measuring oxygen in the exhaust system. Depending on the levels, another sensor reduces or adds fuel to the process.

Catalytic Converter: Located between the silencer and the manifold, it transforms harmful exhaust gases into environmentally friendly ones. Its vital role of turning pollutants into harmless elements makes it a lawfully required component. This means you could be fined for driving a vehicle without a catalytic converter.

Silencer: The silencer, or muffler, is typically fixed at the end of an exhaust system. Besides harmful fumes, the fuel combustion process also produces sound waves. These sound waves cause excessive noise, which is harmful to your neighbours.

The exhaust silencer reduces such noise in two ways: it directs the waves through chambers inside the silencer, causing the waves to cancel each other, or it contains materials that absorb the excessive sound. 

Resonator: Exhaust resonators are specially designed mufflers that produce only certain sounds. These ‘chosen’ sounds are usually appealing to the drivers. Their purpose is not to reduce the noise. Rather, they cancel out the unwanted sound frequencies, keeping only the ‘chosen’ sounds for better appeal.

How does the exhaust affect the MOT? 

Experts suggest car owners include regular exhaust checks in their car service Cheadle. But why is routine exhaustion important? One of the major reasons is its significance in the annual MOT test. This test is a necessary examination of every vehicle in the UK to check its roadworthiness and safety. It also includes checking the emission standards to keep overall pollution under control.

If your vehicle has a faulty exhaust, it can get a ‘fail’ report in its MOT testing. The following are some major faults that can usually fail a vehicle:

• Excessive pollutants: A certain level of pollutants is common in the emission of all vehicles. It is also permissible up to a certain limit. However, illegal levels of pollutants can lead to failure in the MOT.
• Leaks: Another common cause of failure is leaks in the exhaust system. These are safety hazards, and the tester might fail your vehicle.
• Corrosion: Minor corrosion might not be a reason for failure, but it can get you an advisory. On the other hand, excessive corrosion could lead to greater damage to the exhaust system, making it a common reason for failure.
• Missing parts: If your exhaust system has some missing parts, it can get a ‘fail’ report. A missing or damaged DPF or catalytic converter can cause your vehicle to fail its test. 

What are some vital signs of a malfunctioning exhaust system?

Understanding the signs of a malfunctioning exhaust will prevent further damage to your car. Accidents and safety risks are common results of a worn-out exhaust system. Look out for these signs to recognise a malfunctioning exhaust:

• Excessive noise: Any loud gurgling or rattling noises from your car usually indicate a faulty exhaust system.
• Uncomfortable vibrations: Extreme vibrations felt while driving can be uncomfortable for all passengers in a vehicle. This is usually caused by faulty exhaust.
• Pungent smells: A failing gasket can lead to gas leaks. This causes excessive heat generation and burning of the other surrounding components in the system. This is a major cause of the burning smell in your car. Another reason could be leaks in the exhaust system.
• Reduced fuel efficiency: An underlying exhaust malfunction can increase your vehicle’s fuel consumption. This is because the malfunction prevents proper disposal of gases from your car. These gases trap the temperature within the engine, reducing its fuel efficiency.

A smooth driving journey depends on healthy functioning parts and components. This includes optimal working of the exhaust system too. Invest in timely checks for your vehicle to enjoy a comfortable journey ahead.