Diesel Exhaust System


The diesel exhaust system is responsible for exhausting exhaust gases from the engine. It also provides noise attenuation and treatment to reduce emissions. The primary function of diesel exhaust is to collect the used fuel-air mixture in a diesel engine’s combustion chamber and remove it via the tailpipe. It removes exhaust gases from the combustion chambers and reduces noise – the engine may have one or more channels. It is crucial to select the suitable flow resistance to minimize engine performance. The exhaust system must be considered as a whole and designed accordingly. It means that the exhaust system must be compatible with each vehicle and engine.

Also, the exhaust system needs to cope with vibrations from the engine and bodywork – vibrations and jolting from the carriageway. Additionally, exhaust systems should resist internal corrosion attacks caused by hot gases and acid, moisture, splashed water, and saltwater. Furthermore, there is a risk that poisons the catalyst in the presence of sulfur or lead in fuel.

Components of Diesel Exhaust System

  • Exhaust Manifold – This exhaust system component attaches to the cylinder head, taking each cylinder’s exhaust that combines into one pipe. The exhaust manifold can be steel, stainless steel, aluminum, and cast iron.
  • Oxygen Sensor – Modern fuel-injected cars use oxygen sensors to measure the oxygen that the exhaust contains. The computer adds or subtracts fuel to achieve the exact mixture for maximum fuel economy. The oxygen sensor mounts in the exhaust manifold or closer in the exhaust pipe.
  • Catalytic Converter – This component is similar to a muffler that converts damaging carbon monoxide to water vapor and carbon dioxide – some converters reduce harmful nitrogen oxides. Also, this component mounts between the exhaust manifold and the muffler.
  • Muffler/Silencer – Mufflers reduce vehicle noise and control the exhaust gases that come from the engine. Dampers can reduce sound levels in several ways, including resistive silencing and absorptive silencing, as well as shell damping. Additionally, mufflers quiet the exhaust down to its acceptable levels. Most mufflers use baffles for bouncing the exhaust around, evaporating the energy, and lowering the noise. Also, some mufflers use fiberglass packing that absorbs sound energy as the gas flows.
  • Resonator – As the mufflers lower a vehicle’s noise, it does not only work alone all the time. A resonator is part of the inclusion in the components of exhaust systems that works like a mini-muffler. These components are usually straight pipes filled with sound muffling materials. Resonators can be in either before or after the muffler in the exhaust system.
  • Exhaust Pipe – The exhaust tube is the part that carries the gases through the journey to your tailpipe. Despite being made of steel, exhaust tubing can also come in stainless steel, which lasts longer because of its corrosion resistance or aluminized. While aluminized is less resistant to corrosion than plain, it is still better than stainless. It is, however, less expensive than stainless steel.

Identifying Problems in an Exhaust System

Despite being located underneath the vehicle; you need to look out for symptoms in an exhaust system that might indicate some issues with your exhaust.

  • Noises – When you already hear a loud roaring noise, it indicates corrosion to the exhaust system. On the other hand, the hissing sound means that the gas escapes via a crack or a hole in one of the exhaust components. Moreover, a chugging noise means a blockage occurs in one of the pipers. Also, a continuous and rapid succession of knocking sounds indicate that something comes loose in the exhaust.
  • Emissions – A vehicle’s exhaust emissions are unconsumed nitrogen, carbon dioxide, water vapor, and oxygen. If you have spotted white smoke, it is a vapor you can see when you start your car, indicating that the engine is warming up. If you see visible white smoke after the engine is warm, it shows internal leaks or cracks. On the other hand, black smoke is accompanied by increased fuel consumption and maybe a sigh of leaks in the exhaust system, while blue smoke means the oil might be burning in the combustion chamber. It could only mean that the cylinder has leaks present in the valve seals.
  • Visual – To identify the problem with the exhaust system, the best thing to do is to inspect the exhaust to see signs of rust or corrosion. Ensure that you keep an eye for cracks and holes so you can directly contact an expert once you spot signs of damage.

An exhaust system is crucial for your vehicle to remove fuel-air mixtures that might cause damage to your car. This article introduced you to be familiar with its components, and you can easily spot issues that might occur in your vehicle.

For more information about diesel exhaust systems and diesel exhaust tips, you can visit Pure Diesel Power at www.puredieselpower.com or call us at 715-254-1833.