Car exhaust system maintenance and repair

What is the role of the exhaust system?

The exhaust system is designed to reduce the speed of combustion gases and their temperature. On the one hand, the exhaust allows controlling the noise level of the vehicle and, on the other hand, limiting the pollutant emissions according to the current legislation.

The exhaust system reaches the normal operating temperature after we have driven at least 5 km and thus very short trips are prone to premature corrosion of the exhaust system. In addition to this, the thermal shocks caused by the succession of frequent engine starts and stops. This wear and tear can result in loud noises from the exhaust.

At present, the exhaust systems are composed of a lot of expensive elements. It includes one (or more) catalytic converter, an oxygen sensor (or more), and even a two-stroke silencer. There is even an exhaust pipe that is not only designed to purify the pipes underneath the car but also it can be made of premium metals, in some cases with the double exhaust pipe.

There are metal heat shields on the chassis that prevent the ignition of dry grass from the exhaust gases.

What are the elements that make the connection between exhaust components?

Some sealing collars and welded points.

What keeps everything in one place in the exhaust system?

A few pieces of rubber and collars. What exactly keeps everything aligned? Those few pieces of rubber and collars. The faults are normal and range from broken rubber to faulty welding points.
Before you suffer the same expensive fate described so far, take the time to do a normal chassis inspection – it’s easy. To get started, lift the vehicle. Now you are ready to take a closer look.

Exhaust buffers

exhaust-system-buffer

Any faulty buffer must be replaced without delay – even if the exhaust system still seems to be suspended. A defective buffer means that when the system moves up and down when in motion, a ripple effect passes through the rubber joints and welding points. Finally, the rubber breaks, and the welding points crack.

Replacing a bad exhaust buffer was previously a simple operation because most companies used the same type that is screwed onto the chassis and fastened to some parts of the exhaust system. Today, the most popular design uses rods welded to pipes, and sometimes to the chassis of the vehicle.

These buffers have a narrow section of rubber that looks like a flattened soccer ball, with holes for the rod at each end of the rubber. The correct welding locates all the components, so the replacement of the rubber part when worn is a direct operation.

You can install a new exhaust pipe, in case the rod comes out of the pipe, but if the exhaust pipe is in good condition, this is an unnecessary task and an expensive replacement. An alternative would be to install a universal buffer, although this may require some improvisation. Look at a nearby hole, maybe the one in the previous buffer.

How to replace a car exhaust buffer?

  • take a universal buffer that can be twisted and tilted and has an adjustable length;
  • attach it to the chassis with a screw (if it is not tight, add a nut) along the hole;
  • then, make the connections around the pipe – it usually works only with a collar and a “U” shaped screw;
  • do not be surprised if part of the collar is welded (belonging to the broken pad) must be cut or its position changed to create space for the collar that will be attached to the universal buffer;
  • it is recommended that the attachments be made as close as possible to the original location in the equipment settings. This will keep the system aligned and it will keep the sense of balance of the whole system. If there is noise when connecting the exhaust system with its chassis or with a component thereof, it should be checked for any underneath faults.
  • the space of the exhaust system is limited, and if there is a need to increase this space, there is the possibility to bend or adjust the original equipment buffer. In case a buffer fitted with the rod is welded to the positions, check if you can bend it with a piece of pipe over the end of the rod. If the buffer is screwed onto the chassis, for example, you can install washers as adjusting elements.

Some older equipment comes with rubber consoles that look like narrow rubber bands. In case the used tape has broken, it can be replaced, but its installation is not just a simple operation to stretch over the remaining bands. The tape is so narrow and rigid that it will be quite difficult to pull it off.

Many of the exhaust systems are equipped with a collar that provides a secure attachment near the transmission. If the collar breaks, or has been removed and has never been replaced, the curvature of the exhaust system may be exacerbated or it may be broken. If a replacement collar cannot be obtained, the worn collar must be repaired. However, replacement is the best choice in this situation.

Protection shields of the exhaust system

car-exhaust-system-protective-shield

The protective shields of the exhaust system are prone to malfunctions when traveling on rough roads. To prevent a fire from occurring, replace anything missing or just hanging. If the protective shield is compromised, unscrew it and check the exhaust system for any damage.

Exhaust joints

exhaust-joints

If there is an intense flow in the up-down direction within the exhaust system due to a defective buffer, the clamps and joints may present faults. If a welding point is cracked at the silencer or a vibration point, then the parts can be replaced. Another alternative to save money would be to cut the exhaust pipe and part of the coupling neck, then install a short connection pipe and attach it to the clamps.

In the situation where a connection made with the help of a collar is not cracked, but there is still leakage of exhaust gas, remove the worn collar. If the ends of the pipes are very distorted, it will be necessary to use a pipe extension device to remodel it.

On the other hand, you can separate the pipes, remove the rust and then apply a sealing layer of the exhaust pipe. Reassemble it and install a high capacity collar, which can tolerate more torque, to create a seamless connection. Many systems are designed with a cord-type joint located at the exhaust manifold or the Y-shaped pipe of the manifold. This joint is made using a spring screw.

Heat can weaken the action of the springs, and the joint can have cracks. Simply try to tighten the screws, but if the springs have been damaged or weakened, replace the screws, you can buy them, with new springs, in specialized auto parts shops.

Exhaust system coupling collar

If a cord type joint is very rusty, it is worth trying to remove it with a strong solvent. Then remove it and check if it can be saved by a cleaning process, installing a new gasket and reassembling with new screws and nuts (drill the rusty bolts if necessary).

Weights with damping role

Some exhaust systems are designed with vibration dampers, represented by the weights attached to the pipes or parts of the cord connection. If the weights with the damping role break or become curved, the exhaust system will vibrate considerably.

This situation will not only generate an uncomfortable journey, but it can affect the lifetime of the joints made by welding or with the help of collars.

Types of exhaust pipes

  • stainless steel
  • aluminum steel
  • aluminum-zinc steel
  • conventional steel (black)

Most car exhaust pipes are made of aluminum steel. This corrosion-resistant steel is much better than black steel. Black steel parts rarely last more than a year, and those made of high quality aluminum steel last up to 3-6 years.

What does an exhaust pipe contain?

Such a pipe is wrapped in a heat-resistant and wear-resistant insulating material, which acts as an absorber of the sound wave (muffler). The sound passing through the holes of different sizes is refracted and compensated in the insulating material.

How do you choose the right exhaust pipe for your car?

This is a very important issue and requires the help of specialists, because in this case all the details are important, from the diameter of the connecting pipes to the size of the box and the length of the pipe.

To properly choose the right exhaust pipe, you need to consider:

  • the model and make of your car;
  • engine power and type;
  • the type and characteristics of the fuel system;
  • the ability to make changes and improvements to the rear bumper.

There are options for sports exhaust pipes, which are designed for specific car models. Often, they do not require modifications and are mounted on a standard mounting system. There are options for different cars, just ask. But anyway, choose what you want.

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