What Does an Exhaust System Actually do?
Depending on the make and model of your vehicle, the layout of your vehicle’s exhaust system may vary, however, all exhausts work in a similar way.
Your exhaust system has three primary functions:
- directing exhaust fumes (all the nasty gases they contain) well away from passengers by pushing them out through the pipe located at the back
- shielding passengers as well as passers-by, from the noise created by the constant stream of explosions, which are part of the fuel-burning process
- cleaning the chemical cocktail that is produced by burning fuel so that it’s less noxious to those exposed to it.
So, if you were to travel in a vehicle that had no exhaust system, not only would this be pretty noisy, it would also be incredibly dangerous.
What are the Main Parts?
Many of us very rarely get down on our hands and knees and look under our vehicles, unless you’re a mechanic of course, so most of us probably only ever see the very end of our exhausts, which is the tail pipe. What we don’t see is the part of the exhaust system that extends about three-quarters of the length under the vehicle.
Depending on the type of fuel a vehicle uses, the length of metalwork includes five or six main components, which are as follows:
- exhaust manifold: connected to the engine, this is the first point of contact for the exhaust gases after they exit the cylinder head, who’s main job to ensure that these gases are channelled safely through the system and expelled at the far end.
- catalytic converter: taking the gases produced and cleansing them of their harmful components, the catalytic converter is located between the manifold and the silencer, with the catalyst itself being the central component of the system.
- diesel particulate filter: from 2009, it became a legal requirement for such engines to be fitted with one of these. They are designed to catch the larger particles of soot, which are unburnt deposits from the combustion process.
- silencer: designed to conceal the noise made by the combustion, this part of the system is usually made of steel coated with aluminum, which helps protect against water, salt, dirt and the elements.
- exhaust pipe: this is effectively a chimney, through which those gases that are left over can escape into the atmosphere.
What can go Wrong with the Exhaust System?
The main culprit for exhaust damage is rust, which can cause a multitude of problems, which given the amount of corrosive materials, this shouldn’t come as a big surprise. Depending on the severity of rust, it can sometimes lead to complete exhaust failure or structural damage. Although it’s rare for corrosion to get so bad that the pipe works loose and drag along the road, this can happen if there is damage to the exhaust system and if this was to happen, you should stop somewhere safe and call for assistance.
There are many other things that could potentially go wrong with your exhaust system but in some instances, an effective solution can be found simply by replacing the part of the exhaust system which has failed. But remember, even though there are a range of products that can be used to effect a temporary repair to an area of bare metal, such as putties, these products do not offer a long-lasting solution.
How might a Faulty Exhaust Affect my Vehicle?
If your exhaust begins to deteriorate, this could lead to reduced fuel efficiency, which is caused by the engine being forced to work harder than it should to produce power. If you notice one day that you’re using more fuel than normal, then it could be worth having your exhaust system checked out to ensure that there is no fault with it, as if there is, this could be the root of your problem.
Another potential problem of having a faulty exhaust system is that it may damage surrounding components. For example, if you have a cracked exhaust pipe, those hot exhaust fumes could begin to leak, blowing straight at other components, which could potentially cause a fire. The impact that this will have on other bits and bobs underneath your vehicle will differ depending on where the crack within the exhaust system is located.
If you find that your exhaust has begun to depreciate significantly, you should ensure that any damage is repaired before your next MOT. If you don’t repair your exhaust or any other parts of your vehicle and it fails its MOT, you may find yourself in a bit of a pickle when it comes to selling it. If you’re looking to sell your car with no MOT, it may prove to be a little tricky but we can help here at Jamjar with our guidance page about the challenges of selling your car without an MOT certificate.