The strange noises in the exhaust They are a relatively common problem in older cars. However, since the exhaust system is made up of several parts, the prices to fix it are very different. It may only be a few euros or you may have to pay several hundred in a workshop.
In this article we are going to explain the different faults that can cause that noise in the exhaust, to give you an idea of what they should charge you. Even if you're lucky, it might be a problem that you can fix yourself buying the piece and dedicating a little time to it.
Why does the exhaust break?
The exhaust system is made up of several parts that, over time, deteriorate and rust. This problem is usually caused by water condensation within the system or by a frequent exposure to salt. The latter occurs on the coast or in areas where salt is regularly thrown on the road to prevent frost.
Naturally, as much of the exhaust system is under the car, it is one of the most vulnerable to shock. Stones and objects thrown on the road, or entering a path where it should not be, can be enough reasons to end up breaking some part of the exhaust.
Symptoms that the exhaust is broken when accelerating
where the exhaust is especially vulnerable to corrosion and shock is in the welded parts. But no matter where it is, a break in the exhaust pipe should be easily noticeable, because it produces abnormal noises that can even be annoying due to their volume. You can hear it at idle and/or when accelerating, depending on the part that is affected. Although the most common is to hear it when we press the accelerator.
This occurs because, as we well know, the escapement is in charge of evacuate all exhaust gases to the atmosphere. So when they pass in greater quantity and at a higher speed, it is when the pieces that cause the noise will sound more.
How to know what causes the noise in the exhaust
However, one should not jump to conclusions. In the escape we can meet elements like the catalyst, particle filter and mufflers, so the fault will have different costs depending on where the break is. In addition it also has together, gums y fasteners several that may have deteriorated leaving some loose tube that collides and causes noise. Therefore, if you want to know where the annoying sound is coming from, the best thing you can do is crouch down and take a look underneath.
The bad thing is that it is not an operation that can be done completely well if you do not have the right elements. Don't even think about raising the car with a simple jack and keep it ripped while you watch. If an elevator is not available, the most reasonable option is to raise the rear axle with some portable car ramps, such as those of Festnight or those of Cartrend.
Once you have it well secured and with the parking brake firmly on, you can calmly look at what is generating the noise. The most frequent breakdowns ordered from lowest to highest cost of repair are:
rubber bands
The rubber bands that hold some part of the exhaust are broken or loose. When this happens, you will notice the loose exhaust pipe noise whose metal parts vibrate and crash against the underside of the car. New tires can be worth between 5 and 20 euros depending on the brand and model.
Joints
Be careful because in case you have leaks through the joints you will not pass the ITV. You will hear a noise in the bottom that is generated by the jingling of parts against each other in the exhaust system. As with tires, new gaskets can also cost between 5 and 20 euros depending on the brand and model.
perforated tubes
The perforations somewhere in the exhaust can be due to metal corrosion and/or a blow. It is easy to detect because it is usually accompanied by some loss of exhaust gases. In this case the price is variable depending on the part of the exhaust that is bad. It can easily fool us if the noise is in the tailpipe near the catalytic converter, because it can sound like the catalytic converter when it's just a nearby pipe.
broken muffler
Whether due to corrosion or knocks, the muffler a car it is also a part that can be easily broken. In these cases the exhaust noise will be greater the larger the opening. In addition, if the break has occurred in the Helmholtz resonator, the explosions that occur inside the engine will be heard much more.
broken catalyst
This part is one of the most expensive parts of the exhaust system. inside has ceramic parts They can easily break with a bad blow. If this is your case, you will notice a tin noise in the exhaust when the loose pieces collide with the steel coating. Fixing this fault can be between 200 and 500 euros depending on the model and brand.
exhaust manifold problem
In this case you will also hear a metallic noise but far from the exhaust. replace a manifold It is a breakdown that can be very expensive, because it is actually an engine repair. The workshop hours will raise the bill to figures between 300 and 800 euros.
What if I don't fix it
It is important to have the exhaust pipe in good condition. If it is broken, the vehicle will not pass the ITV. So you'll have to go through it again, gas test included. That is why it is not worth having the car in this condition. In addition, depending on where the break is, the exhaust gases released will be untreated, so they are much more polluting and harmful to health.
This last will affect you directly every time you park the car in a closed space and, if the problem is in the exhaust manifold, they can even enter the cabin when you turn on the air conditioning.
Images 1 and 4 – Marco Verch, Samu