Your Exhaust System: The Basics and the Common Issuesby KC Martin Automotive on 10/25/17
Your car’s exhaust system is a set of parts that have the VERY important role of taking the toxic gases your amazing vehicle produces and escorting them away from the passengers safely. It’s not a system that really makes the car “GO”, so folks may be unclear on whether a malfunction really NEEDS to be repaired ASAP. Some drivers will not trust their mechanic or will wait until they fail an emission test before they take on an exhaust system issue. Hopefully, we can step through the basics of the exhaust system so that you will know that even this peripheral system needs to be handled with care for the safety of you and your passengers.
How does the exhaust system work?
Your car’s engine can be described as a pump that brings in fuel and air and out of that creates motion (of the car), heat, and exhaust gases. The system begins by taking the heated gases that are by-product of your engine moving them along quickly. Here is the line of parts that make up the system and what each of them do for you:
This can also be called the “exhaust header”, but this part is collection of tubes that take the exhaust from each cylinder on the engine and combine them into one pipe. It can be made of cast iron, or other metals like aluminum or steel, and must be sealed completely at each cylinder in order to keep any of the exhaust from escaping.
The oxygen sensor is mounted in or near the exhaust manifold. It is an electronic device and its role is to measure the proportional amount of oxygen in your exhaust. It sends readings to the management computer in the engine, so it helps to ensure top performance, but also alerts you to excessive levels of emissions. All cars manufactured after 1980 must have an oxygen sensor, and if this component has any issues you will likely fail your emissions test (even if emissions are at normal levels).
The catalytic converter efficiently reduces the amount of toxin in your car’s exhaust. The exhaust that comes into the catalytic converter is a toxic mix of carbon monoxide, nitrogen oxide, and hydrocarbons. Special metals inside of the converter create a chemical reaction that converts these to water vapor and carbon dioxide---much less harmful toxic levels and should now meet government regulations. This part mounts between the exhaust manifold and the muffler.
The Exhaust Pipe
Just a note that the exhaust pipe is what runs between all of these parts on the journey from the engine to the tail pipe. The most important job of the pipe is that it moves the heated exhaust quickly through the system without letting it cool. It is made of steel and over time it can corrode, but the material is supposed to fight very hard against this corrosion to keep the system smooth and intact.
The Muffler is a series of tubes that dissipates the sound coming from your engine and out through the exhaust system. The internal combustion engine is, after all, a lot of contained explosions. This oval chamber must absorb and control the noise, but also allow exhaust to continue flowing smoothly and quickly to the tail pipe. This part also must resist corrosion and also heat retention.
Some of the Main Issues to Look Out For
The most prevalent issue that arises with these parts would be rust or corrosion. This can happen from the inside---lots of short trips can speed the process---and can also come from the outside, which is more prevalent where salt is put on the roads in winter. Upgrading to stainless steel parts can help fight these issues, but it’s only a real concern if these parts have broken down very quickly. Mufflers are the most common part you might see “rust out” and need replacement.
Some of the other common issues are catalytic converters can become clogged. Oxygen Sensors just wear out over time (nothing you can do about it), and most will alert you. They should be changed every 60K miles or so anyhow. Leaks in the exhaust system should be addressed immediately, because they are bad for your car, but dangerous for you---you don’t want to fool around with these gases.
Trust Your Mechanic Or Find One You CAN Trust
This is a line we say often. It’s common that folks will think they are being “upsold” if the car isn’t showing obvious signs of failure yet. A thorough mechanic (a good one), will be able to see signs FAR before there are issues and will recommend replacing parts to upkeep to this important system. The bottom line is: You should trust the recommendations of your mechanic and stay ahead of these issues, and if you can’t trust them, find a mechanic or auto repair shop you CAN trust.
Might we suggest one of our KC Martin Automotive shops in Lynnwood, WA? Thanks for reading our official blog and if you’re in the area, we hope you give us a chance to show you how we look after our customers’ vehicles every day!