Knowing When to Replace Your Muffler

muffler under car
A leak could appear at any point in your exhaust system, especially at the muffler. Getty

Those of you who spend most of your driving time behind the wheel of a car that still offers a hint of new car smell can skip this one and read about keeping your tires filled with air or changing your oil. If your car tends to go bump in the night from time to time and leave you wondering if you’re about to spend another half hour sitting on the side of the road waiting for help, this muffler article may be just what you need to read. 

Signs To Watch Out For

Sound: If you think that your muffler may be wearing out, the sound is your first indicator. You drive your car or truck every day, so nobody knows better than you do when something just doesn’t sound right. If your engine has gotten a little bit louder lately, there’s a good chance that you need to thoroughly inspect the exhaust system. The muffler is often the culprit when it comes to exhaust problems, but if you think something’s up, you should check out the entire system front to back to be sure. On older cars, the muffler may have been replaced two or three times but the rest of the exhaust system — things like the resonator or the catalytic converter — may be original equipment installed at the factory. If this is the case, it might be time for one of those components to fail even though the muffler is still solid. Use your intuition, and always err on the side of caution. Remember, an exhaust leak could lead to build up of carbon monoxide inside your car or truck, a situation that can be deadly. 

Smell: You should really never smell your car’s exhaust while you’re driving along the road or sitting at a traffic light. When there’s a leak in your exhaust system someplace or a hole in your rusty muffler, exhaust gases will leak out and drift upward into your car or truck’s interior. The exhaust is flowing quickly and is under pressure, so even a small perforation in the exhaust system can pump a lot of exhaust out. This can create a dangerous carbon monoxide situation. Winter months are the worst time for exhaust leaks as we're cocooned in our warm vehicle with the heat on for long periods. If you think you're smelling exhaust in the cabin of your car or truck, have the exhaust system inspected right away. There's no good reason to risk carbon monoxide poisoning due to an avoidable exhaust leak. 

Sight: Taking a solid look at your muffler and exhaust system is your last line of defense against an exhaust leak. Remember, if you've been driving your vehicle your exhaust system is going to be very hot! Let it cool for at least an hour before you crawl around underneath or you could suffer a serious burn. To inspect the exhaust system, start at the tail pipe and work your way forward. You're looking for any obvious holes or splits in the system. Areas of obvious rust are problem zones that may be hiding a hole or two. The muffler itself will tend to leak at its manufacturing seams. This means the rim of both ends, the seam along the center, and the points where the pipes enter and exit the muffler. The same goes for your resonator, catalytic converter, and flex pipe or pipes. If you have access to a lift, you can look for an exhaust leak by feeling for leaks with the engine on, but be sure to do this in the company of a seasoned pro as burns are a real possibility. 

The repair: Once you figure out where your exhaust system has failed, you can get it fixed. It's possible to weld up minor holes or splits, but anything bigger than a pinhole usually needs some or all of that section replaced. Muffler and exhaust system work can be done at home, but a muffler shop can make good, short work of a repair that might take you ... forever.