10 Signs You Might Have An Exhaust Leak

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exhaust leak

How can you determine if your vehicle’s exhaust system is leaking? While your nose and ears may sense and detect certain exhaust leaks, they might well not detect other breaches, including those that enable carbon monoxide to enter your car, posing a health risk. A thorough check at the repair shop is the best approach to identify whether your exhaust is leaking.

A leaking exhaust manifold happens in an automobile when exhaust gases leak not from its exhaust system’s tip but from inside it. Exhaust leaks seem to be harmful since the exhaust gases will bypass the primary exhaust system’s components such as the resonator, catalytic converter, and muffler standard on every production automobile.

Right after the exhaust manifold, a catalytic converter cleans the harmful gases to convert them to be more ecologically friendly—toxic car emissions like carbon monoxide and hydrocarbons into cleaner byproducts such as carbon dioxide and water vapor.

In that case, an exhaust leak servicing must be immediately prioritized. Beyond the stinky gases you smell, other toxic gases might be infiltrating your cabin – fumes you cannot smell.

Since these leaks are not always something you can smell, pay close attention to any car’s acceleration ability abnormalities.

Common Signs and Symptoms of an Exhaust Leak

  • Strange Odor
  • Clicking or Tapping Noise
  • Engine Noise Getting Louder
  • Reduced Fuel Economy
  • Vibrating Gas Pedal
  • Strange Loud Noise When Accelerating
  • Poor Engine Performance
  • Visible Defects
  • Failed Emission Test
  • Check Engine Light

Signs and Symptoms Of An Exhaust Leak

exhaust leak symptoms

The most prevalent leak indicator is a ripping noise from the engine bay or beneath your automobile. Additionally, if there is a significant leak, your car sound may become strangely noisier than usual. Also, you may notice a check engine light and a decrease in performance. If you fear that your car’s exhaust has begun leaking fumes, review the list below to determine the source of the exhaust problem.

Strange Odor

This is a classic and one of the pronounced symptoms; you can smell exhaust fumes when your car is running. As indicated before, your car’s exhaust system was engineered to avoid this.

Therefore, if you start to detect an unusual exhaust odor, something on your exhaust is damaged, and the gases can no longer be contained. Prolonged exposure and breathing with exhaust fumes can be very damaging. If you start to smell the stench of exhaust fumes, make it a priority to repair leaks as quickly as possible.

Clicking or Tapping Sound

A leaking exhaust manifold will often produce a clicking or tapping noise. Frequently, the noise is more audible during a cold start. The noise may decrease or vanish when the engine heats up and expands the exhaust manifold.

Engine Noise Getting Louder

Another indicator of an exhaust leak is that your engine and exhaust system makes a noisier sound than average. You’ll notice one or two sets of mufflers on the exhaust system that significantly reduce engine noise.

If a leak happens before one of such mufflers, they will not muffle the noise since the exhaust will stream out to the leak before them. This results in louder noise, depending on the size of the leakage.

Reduced Fuel Economy

When airflow is restricted via the exhaust, your engine might have to work much harder to produce the same level of power. This results in poor fuel efficiency. If you observe a decrease in performance and more fuel consumption, a leakage is probably the cause.

Vibrating Gas Pedal

Your automobile will vibrate whenever there is even the slightest leak. However, these vibrations can also be substantial if the leak is significant. You will initially become aware of these vibrations emanating from your gas pedal.

If nothing is done, vibrations would be sensed on the steering wheel. Eventually, vibrations will be felt through your flooring.

Strange Noise When Accelerating

Lay your foot on the gas pedal and listen carefully to any strange sounds. You almost certainly have a problem when you hear noises similar to air escaping or perhaps whistling. However, most individuals have difficulty distinguishing between exhaust sounds, various engine sounds, and even a vacuum line leak.

Not just that, but a variety of different issues might cause weird sounds. Consider this indication only when you’ve previously encountered other symptoms and seeking confirmation of your concerns.

Poor Engine Performance

The similar stands true with a check engine light. If an exhaust leak occurs before one of those sensors on your exhaust pipe, they can register incorrect readings and communicate inaccurate data to the ECU (Engine Control Unit.) Also, It may cause your automobile to operate badly and may cause it to lose power.

Your ECU will then use this data to determine the air/fuel mixture of the following cycle of the engine, and since the figures are incorrect, even bizarre air/fuel mixture will follow. This might result in a rough idle, poor acceleration, and cylinder misfires.

If you notice your car making a strange noise than usual with poor performance, it is undoubtedly time to visit an auto repair shop and search for any leak.

Visible Defects

The studs, screws, or nuts that secure the exhaust manifold towards the cylinder head might rust and disintegrate over time, resulting in a leak. Additionally, a deformed exhaust manifold might cause the bolts to over-extend and snap off.

Also, black stains and burned components around the source of the leak are indications of a leaking exhaust manifold. You also may notice apparent fractures in the exhaust manifold as you conduct a visual inspection.

Failed Emission Test

To legally run your vehicle on the streets, you must do and pass an annual emission test; however, if there is a leak in your exhaust system, it’ll impact the test result.

When the leak occurs before your oxygen sensors, it’ll affect the air/fuel mixture; if the leak occurs after such sensors, the test will indicate an abnormally lean mixture, and you’ll probably flunk the test, relying on the severity of your leak.

Check Engine Light

Modern automobiles are equipped with sensors within the exhaust system that monitor the gas mixture emitted by the engine. One of such sensors can evaluate the catalytic converter’s efficacy. These are referred to as Oxygen Sensors.

When a leak occurs before any of such sensors, it’ll make them read incorrect measurements, which the ECU will acknowledge. This can trigger the check engine light on your dashboard.

Why Are Exhaust Leaks Hazardous and Damaging?

exhaust pipes

Exhaust leaks are obnoxious, inconvenient, and embarrassing. You don’t want to alert everyone about your arrival on each street you drive down, particularly if you’re just on your way to work.

Of course, the noise is not the only cause to repair a leak. This typical issue might also be dangerous to you and your automobile in the future.

If you’ve made a habit of disregarding issues, it might be essential to rethink your strategy. The following are reasons why an exhaust leak might result in considerably more severe problems down the road.

Engine Damage

Under the worst situation, if the exhaust leak occurs in any sensitive areas might result in costly internal engine damage. If your exhaust system transports gases far from the engine, it executes a function other than just moving dangerous substances.

Additionally, the exhaust stream drives away heat generated in the combustion chambers. If an exhaust leak develops near the exhaust manifold, the system’s ability to expel heat from the engine is compromised.

This extra heat can harm the valves that enable the fumes to exit. This kind of internal engine damage often costs considerably over $1,000, significantly outnumbers the cost of fixing the leak in the first place.

Harmful Emissions

Once you smell exhaust vapors inside your automobile, this indicates that dangerous exhaust gases are flowing throughout the cabin. The conventional passenger car is not airtightly sealed and depends on its exhaust system to securely evacuate gases from its rear.

On the other hand, if the emissions are exiting from underneath the car, it frequently finds their way into the passenger compartment. Carbon monoxide is among the most hazardous combustion byproducts, ultimately a silent killer.

If a dangerous amount of this gas seeps into your vehicle, you may be unaware of the situation. While these leaks may be expensive for various causes, cabin leakage poses the most significant hazard to drivers and passengers’ health.

Bad Oxygen Sensor

Excess gasoline in the exhaust stream may cover the sensor tips, clogging them and impairing their ability to provide an accurate measurement.

The more you overlook a leak, the more likely it is that your O2 sensors may need replacement as well. In addition to the service expense, a malfunctioning O2 sensor reduces your car’s gas economy, depletes the engine’s power, and may cause your car to idle roughly.

Additionally, you may generate many system error codes, complicating determining the root cause of the issue.

Cat Converter Deficiency

A leaky exhaust system may cause more than simply a failure to remove combustion waste from your motor. Additionally, it has the potential to suck extra oxygen through the system. Once this occurs, your vehicle’s O2 sensor detects a lean state and adjusts by adding more gas to the combustion mixture.

Because there is not enough air to combust all of this gas, unburned gas will penetrate your exhaust stream. While any excess gas may seem benign, unburned gas poses a danger to your vehicle’s catalytic converters.

Due to the extraordinarily high temperatures at which cat converters work, unburned gas would combust as it reaches them. This wears down the internal layer over time, obstructing the device and preventing it from working correctly.

How To Fix An Exhaust Leak

If you detect a leak in your exhaust, it may be tough to repair. You might undoubtedly seek an assessment from an experienced mechanic to better understand the situation. You might be prepared to replace a part of the system’s components.

This can be accomplished by disabling the connections and replacing the damaged piece. This is only an alternative if the whole system does not need to be replaced. The disadvantage is that it is almost always costly and may be challenging to complete due to the rusty studs, bolts, and other components. The best approach is to bring your car to a reputable auto repair facility where a new part of the pipes may be welded in for you.

They will ensure that your entire system is leak-free. Additionally, you always have the choice of replacing the whole system. A mechanic would often propose this since there is no assurance that welding would survive for an extended period. If you choose to replace the entire system or just the leak is totally up to you and is determined by the severity of the leak.

Exhaust Leak Repair Cost

Exhaust leaks must be repaired immediately. It would be best to budget between $160 up to $300. You can handle it yourself if the leak’s source is simple to fix.

But, if you find that the leak is triggered by a crack or fracture in the exhaust system, you should get it repaired by a muffler repair shop. Experts can repair the damage or replace the pipe, ensuring that your car’s exhaust system is leak-free. Usually, it takes two to three hours to fix such a leak. If the problem is simple to address, it can take minimal time.

However, if the leak’s origin is unknown or if the leak is challenging to fix, it could take longer. The cost of repairing a leaky exhaust will be higher in this situation. You may need to replace the whole system’s pipe to cure the leak completely.

In such a situation, budget between $750 up to $800. This includes both labor and parts. Additionally, the cost may increase or decrease based on your location, the shop, and the make and model of your vehicle.


An exhaust leak can be hazardous since they allow exhaust gases to enter your vehicle’s cabin. Breathing car emission fumes may produce temporary pain and result in serious health concerns, even death!

If you notice odd fumes in your automobile, you must seek quick assistance from an experienced mechanic or a reputable auto shop. 


Can you drive a car with an exhaust leak?

Driving your car with an exhaust leak might be unsafe due to carbon monoxide in the emissions. Such a leak could reduce gas mileage, forcing the engine to perform harder, leading to internal engine damage.

What happens if there is an exhaust leak?

A leak can negatively impact the air/fuel mixture ratio. An incorrect ratio may lead the engine to perform more inefficiently, lowering the engine’s general performance.

What do exhaust leaks sound like?

You may hear a spraying or tapping sound if you’ve got a defective exhaust manifold gasket. The sound is particularly audible after a cold engine start or whenever the car accelerates.

Would an Exhaust Leak show an error code?

Perhaps, relying on the leak’s location. A code will be triggered if a leak is large enough to affect oxygen levels.

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