All too often forgotten by motorists, the exhaust system plays an essential part in the proper running of your engine. It reduces noise pollution and helps to reduce pollutant emissions. For this reason, it should be checked and cared for regularly, in particular to make it easier for your car to pass the roadworthiness test.
WHAT IS THE EXHAUST SYSTEM?
As the final stage in the fuel’s route through the vehicle, the exhaust system is more commonly referred to as the system that redirects the combustion gases from the engine to the outside of the vehicle.
Its components vary depending on whether it is a petrol or diesel engine, an old or new car, but in all cases, will always include the following:
- The exhaust manifold, which receives the gases directly emitted by the engine.
- The catalyzer or catalytic converter is a key component that has been compulsory since 1997 and which transforms toxic exhaust gases into carbon dioxide and water.
- The DPF (on diesel cars), which blocks fine particles containing carbon.
- The front silencer or expansion pipe, which slows down and cools the gases after catalysis.
- The rear silencer or exhaust pipe, which minimises noise pollution before the gases leave the engine. .
The exhaust system operation starts at the rear of the engine block at the front of the vehicle. The manifold, attached to the cylinder head, receives the exhaust gases from the engine and conveys the heat to the rear of the vehicle to amplify the oxidation of the unconsumed hydrocarbons and carbon monoxide.
The exhaust gases then pass through the catalytic converter, which converts the toxic gases into carbon dioxide and water vapour through catalysts. It eliminates more than 90% of the most harmful gases.
Once most of the toxic gases have been eliminated, the exhaust pipe takes over and draws them into the resonance chambers to reduce exhaust noise. The gases emanating from the exhaust pipe are thus much less toxic and noisy than those coming from the engine.
The main causes of impairments
Like all the parts comprising your vehicle, the exhaust system is also subject to wear. Corrosion, high temperatures and shocks are the main causes.
Corrosion may be internal (related to factors inside the vehicle) or external (related to outside factors). Internal corrosion is mainly caused by driving in an urban environment. Indeed, during short trips, the condensation from starting is not eliminated, the exhaust pipe fills with acid-laden water which attacks the internal walls causing corrosion.
External corrosion occurs when the outer casing of the exhaust system is exposed to water, mud and salt, causing oxidation.
Even when the engine is running, the exhaust system reaches very high temperatures. For example, when driving at 130 km/h, the interior temperature can rise to 900°C. This temperature difference between the exhaust system and the outside air also causes a deterioration of the system.
Finally, like all car parts, the exhaust system is subject to shocks during driving (potholes, speed bumps, pavements), which over time subjects the various components to wear and tear.
The main signs of exhaust system failure:
- Abnormal noises when the engine is running
Vibration or rattling noises at floor level
Loss of power
- Excessive fuel consumption
Our expert advice on caring for your exhaust system
To prevent your exhaust system from deteriorating, we strongly advise you to drive long journeys on a regular basis to increase proper moisture evaporation.
If the car’s “minimum fuel” indicator light comes on, avoid driving it for too long. Indeed, the irregular supply of fuel to the engine deteriorates the catalytic converter.
– METAL 5 – EGR VALVE CLEANER
– METAL 5 – EGR VALVE CLEANING KIT
– METAL 5 – DIESEL POLLUTION REDUCTION PERFORMANCE PACK
– METAL 5 – DIESEL DPF REGENERATING CLEANER
– METAL 5 INTÉGRAL
– METAL 5 INTÉGRAL – CORRECTIVE (2 DOSES)
– BELGOM – CHROME
– BELGOM – ALU