Common Signs of an Exhaust Leak

The exhaust system on all vehicles powered by an internal combustion engine, whether gasoline or diesel, is tasked with expelling the toxic gases produced in the engine's combustion process out and away from the vehicle. Understanding common exhaust leak symptoms helps drivers identify issues early.

The components of your car's exhaust include the exhaust manifold, the catalytic converter that reduces harmful emissions, the various mufflers fitted to quiet excessive engine noise, and the exhaust tips.

The engineered design of the exhaust system, from the exhaust manifold all the way to the exhaust tip, helps optimize the flow of exhaust gases that not only work to increase the engine's performance but also optimize your vehicle's fuel efficiency.

All is well until there's a leak in your car's exhaust.

We take an in-depth look at the common signs of an exhaust leak on your car and how it affects both you and your vehicle.

Causes of Exhaust Leaks

Like the rest of any modern gasoline or diesel-powered vehicle, the exhaust system of your car is subject to all kinds of damage from vibrations, moisture, road salt, and road debris.

Exhaust leaks are commonly caused by corrosion, failing gaskets, and physical damage, which includes the welds, along with general wear and tear from age and repeated heat cycles.

Repeated heating and cooling as your engine is started and stopped can cause the metal to crack and the gaskets to deteriorate, which eventually leads to leaks in the various exhaust components, including the exhaust manifold, the catalytic converter, mufflers, pipes, and exhaust tip.

How Do I Tell If I Have an Exhaust Leak?

Let's take a look at a few sure signs car owners should be on the lookout for, especially the most common exhaust leak symptoms that can alert you to a problem.

Louder Engine Noise

A leak in your vehicle's exhaust will cause the exhaust to emit louder than usual noise, making it one of the clearest early exhaust leak symptoms to notice.

Unusual noises can include a louder-than-usual rumbling, along with other odd sounds like hissing, tapping, popping, or even a rattling sound, especially noticeable when accelerating.

Unusual Vibrations

Your vehicle's gas pedal or steering wheel may vibrate more than usual as the exhaust gases escape from places in the exhaust system that they weren't meant to come from.

Reduced Engine Performance

As mentioned, the exhaust system in your car, or rather under your car, is integral to the performance of your vehicle, especially if your vehicle is a performance car and the exhaust is specially tuned to increase horsepower and torque figures.

It goes without saying that any leaks in the exhaust will disrupt the correct flow of gases and lead to a loss of performance.

Decreased Fuel Efficiency

Not only is the engine's overall performance affected by an exhaust leak, but the fact that your engine is having to work harder to offer its normal performance levels means that more fuel is being used, making reduced fuel economy one of the more hidden exhaust leak symptoms drivers often overlook.

Strong Exhaust or Fuel Smell

Normally, your vehicle's exhaust system expels the spent toxic exhaust gases out the rear of your vehicle, where they cannot be smelled in the cabin. An exhaust leak, however, will easily cause these gases to enter the cabin, creating one of the most dangerous exhaust leak symptoms due to exposure to harmful fumes.

Exhaust gases are very much unwelcome in your passenger space as they can cause headaches, dizziness, nausea, and respiratory issues.

These unwanted smells from exhaust fumes contain many pollutants like carbon monoxide, nitrogen oxides, sulfur dioxide, and various hydrocarbons, including benzene and formaldehyde, along with fine soot particles.

Illuminated Check Engine Light

Your car's exhaust system also makes use of sensors such as the oxygen sensors normally located before the catalytic converter and further downstream that monitor the exhaust gases.

An exhaust leak can affect these oxygen sensors, triggering a fault code and causing the Check Engine Light to come on.

Failed Emissions Test

If you have to have an emission test done on your vehicle, a leaking exhaust can very well cause your vehicle to fail the emissions test.

Visible Signs of Exhaust Damage

A quick visual inspection can reveal any exhaust damage that is the cause of an exhaust leak.

Taking your vehicle to any professional workshop and placing it on a vehicle hoist will allow the exhaust to be inspected. Damage from rocks or speed bumps can lead to damage to the various parts of the exhaust system.

Rust or Corrosion on Exhaust Components

Unless your vehicle's exhaust system is constructed of stainless steel, the chances of rust and corrosion causing a leak in mild steel exhausts are high, especially in higher mileage and older vehicles, and rust perforation often contributes directly to visible exhaust leak symptoms.

Vehicles that operate in wetter climates or areas where roads are salted will be more susceptible to corrosion, with a higher chance of the exhaust parts perforating from rust and eventually leaking.

Black Soot Around Joints or Connections

Soot is emitted from your car's exhaust during the combustion process, and any leaks around the joints or connections can be seen as black soot patches.

Deteriorating gaskets on the exhaust manifold can be easily spotted as black soot builds up around the joint between the manifold and engine.

Cracks or Holes in the Exhaust System

Cracks or holes in the exhaust system are a sure sign that your exhaust is leaking. Damage from road debris can cause cracks and holes.

Owners who use their vehicles in more extreme off-road conditions are more likely to experience cracks and holes as they navigate rocky trails and other exhaust-unfriendly terrain.

Safety Risks of Ignoring an Exhaust Leak

As already shared, exhaust gases entering your vehicle's cabin are not ideal at all. Depending on where the exhaust leak is located, toxic gases may be sucked into the interior of your vehicle and cause harm to you and your passengers' health, making cabin contamination one of the most hazardous exhaust leak symptoms.

Not attending to an exhaust leak immediately poses severe safety risks, primarily the danger of carbon monoxide poisoning, which can be fatal. Carbon monoxide can seep into the passenger area through the air vents, door seams, or floor pan, especially when idling or in stop-and-go traffic.

Without being too macabre here, think of those poor souls who choose to end their lives sitting in their running cars in their garages. You certainly don't want to inadvertently end up gassing yourself by ignoring that exhaust leak.

Is it Okay to Drive With an Exhaust Leak?

Not really okay at all, as we've already learned. Your car's performance suffers, your fuel economy suffers, your neighbors will start hating you as your noisy car starts up in the morning, and you will also catch the attention of your local police.

Most importantly, you don't want to be subjected to the possibility of harmful toxic gases entering the cabin of your car while driving, which may very quickly lead to drowsiness with the heightened risk of an accident or health issues.

How Exhaust Leaks Are Diagnosed

When you suspect that your vehicle has developed an exhaust leak and you don't have the means or the mechanical knowledge to carry out any DIY diagnosis, it's best to seek professional help.

Suitably qualified technicians can diagnose an exhaust leak by employing a few different methods.

Visual Inspections

A visual inspection may be a quick and inexpensive means to check for exhaust leaks. This does, however, require accessing the underside of your vehicle with a suitable hoist or car ramp in a properly equipped workshop or service center.

Soapy Water Test

This method may seem a tad weird, but old-school methods often work the best.

The soapy water test involves spraying soapy water onto the suspected area of the exhaust leak and then lightly pressurizing the exhaust with an air pump or air compressor line to check for bubbles to identify the area of the exhaust leak.

This test must, however, be carried out on a cool exhaust as a hot exhaust will quickly turn the soapy solution into steam.

Professional Diagnostic Methods

Professional diagnostic methods for exhaust leak detection include the use of a smoke machine to pressurize the system with smoke that allows the leaks to be made visible.

Professional workshop technicians may also make use of a mechanic's stethoscope to listen for any unusual sounds from an exhaust leak.

Professional diagnostics also include the use of an OBD diagnostic scanning tool that is connected to the vehicle's ECU to identify related problems such as the aforementioned "check engine" light.

Get Your Exhaust Leak Serviced at Colonial Chevrolet

Having now learned more about exhaust leak symptoms and how they can impact your vehicle, next time your Chevy starts to sound a bit noisier than normal, be sure to contact the service center at Colonial Chevrolet in New London, CT, for a prompt exhaust leak repair.

Colonial Chevrolet's certified service center is always ready to provide customers with a great customer service experience.

Our dealership's skilled technicians will ensure that your Chevy receives the correct and most convenient repair, and when it comes to replacing parts in your Chevy, we recommend the use of genuine OEM parts from GM designed and manufactured for your specific Chevy model to ensure a correct fit and proper functioning.