Why Does My Car Sound Like a Lawnmower?

You wake up one morning, get in your car, and upon turning the key you hear an unsettling noise. When you drove yesterday, your car was quiet and composed, but now it sounds loud and choppy like a riding lawn mower. Not only is it embarrassing to drive around with your car in this condition, but it could also be a health risk.

Cars make distinct noises when experiencing certain issues, such as squeaking brakes or clunking suspension. It can be relatively easy to identify the cause of these sorts of sounds. When your car starts to sound like a lawnmower, the problem typically lies somewhere in the exhaust system. With exhaust piping running the length of the vehicle, there are many places it could be leaking from.

What Causes My Car to Sound This Rough?

In cases like these, the source of the problem can often be traced back to a leak from the exhaust. When your exhaust system leaks, it lets exhaust gasses and unmuffled sound escape before reaching parts of the system like the catalytic converters, resonators, or mufflers. 

Exhaust leaks can not only cause problems in terms of noise but also render your vehicle unable to pass smog inspections and technically illegal to drive on the street. If the exhaust leak is allowing toxic fumes to enter the cabin, it can also pose a risk to your health and safety. 

Where is My Leak?

Unfortunately, locating the leak in your exhaust system can be difficult. As the exhaust system stretches the length of the whole vehicle in most cases, there are various failure points where it could be allowing excess sound and gasses to escape. 

Oftentimes these leaks will be formed in a connection somewhere in the exhaust system, whether that be a weld or clamp. Leaks can form easily in exhaust components like the resonators or mufflers, where rust or physical damage can cause holes or cracks in the airtight system.

Depending on the severity of the leak, you may need to either repair or fully replace the component. Luckily, these parts are only responsible for regulating sound and are located after the catalytic converters within the exhaust system, meaning if these parts are the culprit, the exhaust gasses being emitted are still passing through the catalytic converters..

Catalytic Converter Issues

Probably the most serious cause of a vehicle sounding much louder and rougher than normal is the catalytic converter, or lack thereof specifically. Catalytic converters are responsible for “cleaning” your engine’s exhaust gasses before they’re emitted by inducing a chemical reaction between these toxic gasses and the precious metals in the catalyst. 

Due to their high rare metal content, such as palladium and platinum, catalytic converters are a prime target for criminals looking to make a quick and dirty buck. This means that catalytic converter theft has seen a huge rise in popularity and has left many without their expensive component, a quiet engine, or the ability to pass smog. 

Santeri Viinamäki, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

When the catalytic converter is stolen or broken off, it means the engine will be dumping completely unfiltered smog from under the vehicle, as well as producing loud noise and creating a sound similar to an old lawnmower or gas chainsaw. 

If you turn your car on one morning and notice this noise out of nowhere, take a look at your exhaust pipes below to see if you’re missing this important section of your exhaust.

That said, not all catalytic converter issues are caused by theft. These metal components can wear, rust, and break just like resonators or mufflers which can cause similar problems to it missing altogether. Faulty catalytic converters should be repaired or replaced immediately to protect your engine, ensure you’re able to pass emissions and prevent harmful gasses from reaching the atmosphere. 

Getting it Fixed

If you notice an increase in your vehicle’s noise, especially a drastic one, you should have it inspected by a professional immediately.

While noises serve as great indicators for certain problems in a vehicle, the only way to truly diagnose the issue is to have it looked at and repaired by someone with the proper expertise. A quality repair shop may be able to repair sections of your exhaust if they’re slightly leaking, while failed or missing parts will need to be replaced entirely. 

Exhaust Service in Carlsbad

If you’re experiencing worrying noises from your vehicle, trust the experts at Carlsbad Auto Service to diagnose and repair yours. Our expert technicians have decades of experience dealing with emissions systems and exhaust components, meaning we’ll be able to locate the source of your problem and return your vehicle to sound healthy and normal. 

Call or schedule at our repair shop in Carlsbad today!

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