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Exhaust Leak: What Is It, Signs & How to Fix (Complete Guide)

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  • 6 min read

Last Updated on: 7th September 2023, 12:45 am

If your car has been diagnosed with an exhaust leak, you may have some unanswered concerns about how it will effect its performance and if it is safe to drive.

An exhaust leak can vary in intensity, but they nearly always cause one or more obvious signs.

If you don’t have it addressed right away, it might lead to further issues with your car later on which is why it is best to get an auto repair shop to fix this issue quickly.

What Is an Exhaust Leak?

When some of the exhaust gases created within the engine’s combustion chamber seep out of your vehicle’s exhaust system before reaching the tailpipe, it’s called an exhaust leak.

Exhaust gases are discharged from the tailpipe of healthy cars. Unfortunately, some of these gases can seep out before reaching the end of the exhaust.

An “exhaust leak” occurs when exhaust gases seep out between the engine’s combustion chamber and the tailpipe.

A leak in the exhaust can occur anywhere, such as at a flange where bolts have come loose, from a rusty part of the pipe, or even a crack in the metal, etc.

Exhaust leaks are a concern for a variety of reasons:

  1. For starters, they may skew sensors, causing your engine to consume too much or too little fuel.
  2. Second, exhaust leaks are harmful to the environment because they typically allow exhaust gases to escape before passing through the catalytic converter.
  3. They might endanger your health and that of your passengers if exhaust gasses enter the cabin, which can happen if the exhaust leak is closer to the engine bay.
exhaust leak

Signs & Symptoms

There are multiple warning signs of an exhaust leak, below are some of the most common symptoms.

  1. Louder engine and exhaust
  2. Excessive vibrations
  3. Reduced fuel efficiency
  4. Hissing and other unusual sounds
  5. Stronger smell of fuel

1. Louder Engine & Exhaust

The obvious indicator of an exhaust manifold gasket leak is when you start the engine and hear an increasingly loud noise emanating from around the engine.

Keep in mind that a gasket connects the exhaust manifold pipe to the engine block. This gasket, like the pipe, is continually heated and cooled.

If you don’t notice a fracture or leak coming from the pipe, look at the gasket to determine if it has a fault.

It will usually sound louder upon acceleration and cold start.

2. Excessive Vibrations

You may feel excessive vibrations coming from the pedals, the steering wheel, the seat and possibly the whole car may drone.

Typically the larger the exhaust leak the louder and harsher the vibrations will be.

3. Reduced Fuel Efficiency

Sometimes an exhaust leak will skew with the various sensors of the car, which can change the air fuel ratio the ECU uses, making the engine run less efficient.

This is usually a gradually worsening symptom of an exhaust leak and may not be as noticeable.

4. Hissing / Unusual Sounds

Place your foot on the gas pedal and listen for any sounds that don’t sound correct. You have a problem if you hear noises that seem like air escaping out, whistling, hissing, and other unusual sounds.

Most individuals, however, have difficulty distinguishing between distinct engine noises, exhaust sounds, or even a vacuum line leak.

Not only that, but weird engine sounds might also be the result of other issues with the engine.

Use this indicator only if you’ve previously had another symptom and want to confirm your concerns.

5. Stronger Smell of Fuel / Emissions

Carbon monoxide is the only odourless exhaust fume but it is very dangerous. You’ll notice a strong smell inside or outside your car if your exhaust manifold is leaking.

If the odour lingers, it is most likely dangerous exhaust fumes that you should avoid breathing in for an extended period of time.

As a result, take your car to an auto repair shop as soon as possible to have the issue diagnosed and fixed. Make sure your windows are open while driving.

Carbon monoxide may be deadly, so don’t take any risks with it.

Can You Drive With an Exhaust Leak?

While it is feasible, you should not drive your car if you are aware that it has an exhaust leak.

While increased noise, vibrations, and poor gas economy may be minor irritations, carbon monoxide poisoning is no laughing matter.

You may believe that you are safe from poisonous exhaust fumes within the car’s cabin, but the inside is not airtight, allowing carbon monoxide to slowly creep in but having a difficult time exiting.

You may also have an exhaust leak near to your cabin filter air intake, giving a direct path for exhaust gasses to enter your vehicle.

Exhaust gases may induce headaches, weariness, and disorientation, all of which might lead to an accident. Carbon monoxide poisoning may be fatal if left untreated for lengthy periods of time.

If you’re experiencing any of the symptoms listed above (particularly if you can smell exhaust fumes in the cabin), you should take your vehicle to an auto repair or muffler shop as soon as possible.

You should avoid driving with an exhaust leak, however if you have to drive, always drive with your windows open if you suspect an exhaust leak.

How to Fix an Exhaust Leak

It will be tough to repair a leak that is caused by a crack or hole in your exhaust system on your own.

By detaching the two close joints and replacing the complete piece of exhaust, you may be able to replace only the portion of pipe or exhaust component.

However, this approach is often costly and difficult to implement due to rusty fasteners and connections.

In this scenario, the best course of action is to take your car to a repair shop where a new length of pipe or component may be welded in to ensure that your exhaust system is leak-free.

As stated above, exhaust leaks may be very harmful since they allow exhaust gases to enter your vehicle’s interior.

Exhaust gases are not only harmful to the environment, but they are also very harmful to your health.

  • Andy Lewin

    Andy Lewin is a senior mechanic, ASE qualified master technician, and an experienced automotive engineer. He's passionate about serving the automotive community with the highest-quality and trustworthy information on all things automotive. He loves to write about car repairs, maintenance, car modifications and tuning, faults, and much more.

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