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Exhaust Leak Symptoms

Updated: Jan 9

If your vehicle has an exhaust leak, you might be worried about how it will affect its performance and if it is still safe to drive. In this article, we'll explore exhaust leak symptoms, how to find an exhaust leak, and if it's safe to drive with one.

Although exhaust leaks can range in severity, one or more symptoms are almost always present. It is advisable to have an automotive repair shop to fix this issue soon since if you don't, it can cause further problems with your vehicle in the future.

Exhaust leaks are also harmful to car occupants; if you suspect an exhaust leak, avoid driving, but if you must, keep your windows open while the engine is running.


Table of Contents:

car exhaust

What Is an Exhaust Leak?

An exhaust leak occurs when a portion of the exhaust gases produced in the combustion chamber of your engine escapes the exhaust system of your car before exiting via the tailpipe.

Functioning vehicles release exhaust gases from the tailpipe. Unfortunately, some of these gases can escape before reaching the end of the exhaust. When exhaust gases seep out between the engine's combustion chamber and the tailpipe, this is referred to as a "exhaust leak".

Anywhere bolts have come loose, a rusty section of the pipe, a crack in the metal, etc., there is a chance that an exhaust leak may develop.

Exhaust leaks are an issue for a variety of reasons.

  • They may disrupt sensors, that could cause your engine use too much or too little fuel and an exhaust leak can cause a check engine light.

  • Since they often enable exhaust gases to escape before going through the catalytic converter, exhaust leaks are harmful to the environment.

  • They could risk your health and those of your passengers if exhaust fumes reach the cabin, which can happen if the exhaust leak is closer to the engine bay.

Exhaust Leak Symptoms

The following list includes some of the most typical signs of an exhaust leak. You may notice one or more of these signs.

  • A louder exhaust and engine

  • Increased vibrations

  • Decreased fuel efficiency

  • Reduced power and acceleration

  • Unusual noises, including hissing, rattling and tapping

  • A smell of fuel

  • Check engine light

A Louder Exhaust & Engine

When you start the engine and notice an increasingly loud noise coming from the engine area, this is a strong indicator that the exhaust manifold gasket is leaking.

Remember that a gasket seals the gap between the engine block and the exhaust manifold pipe. Like the pipe, this gasket undergoes constant heating and cooling.

If there isn't a crack or leak coming from the pipe, check the gasket to see if it's broken. Normally, it will sound louder when accelerating and when it first starts (cold start).

Increased Vibrations

The pedals, the steering wheel, the seat, and perhaps the entire car may drone if there are too many vibrations.

The vibrations will often be louder and rougher the bigger the exhaust leak.

Decreased Fuel Efficiency

Sometimes an exhaust leak will interfere with the car's different sensors, changing the air-to-fuel ratio the ECU calculates and causing the engine to operate less efficiently.

This exhaust leak indication typically becomes worse with time and may not be as obvious.

Reduced Power and Acceleration

A leaking exhaust system can cause a loss of power and can reduce acceleration, top speed and the general performance of an engine.

This could be due to affecting the various sensors found within the exhaust, reducing exhaust gas flow through the turbocharger (if the exhaust leak is before the turbo), or it could be the ECU putting the engine into limp mode.

Unusual Sounds

Put your foot down on the accelerator pedal and listen for any unusual noises. If you hear sounds like air escaping, whistling, hissing, rattling, tapping or other strange noises, you may have a problem with the exhaust.

However, most people find it difficult to differentiate between various engine noises, exhaust noises, or even a vacuum line leak. Additionally, unusual engine noises might be the result of other engine problems.

A Smell of Fuel

The only odourless exhaust fume, carbon monoxide, is also the most hazardous. If your exhaust manifold is leaking, you'll notice a strong smell either within or outside of your vehicle. If the smell persists, it is probably hazardous exhaust fumes that you should avoid breathing.

Take your vehicle to an automotive repair shop as soon as you can to have the problem identified and fixed. While driving, make sure the windows are open and there is plenty of air flow.

Don't take any chances with carbon monoxide since it can be fatal if you breathe it in.

Check Engine Light

The check engine light is a warning light that alerts the driver when there is a problem with the vehicle's emissions system or powertrain. This light is located on the dashboard and is activated by the engine control unit (ECU) if an issue is detected.

The ECU is able to detect a range of issues, including an exhaust leak. If an exhaust leak is present, the oxygen sensors in the exhaust system can send incorrect data to the ECU, causing it to trigger the check engine light.

In other words, the check engine light can be activated by an exhaust leak if the ECU detects an issue with the exhaust system through the oxygen sensors.

What Does an Exhaust Leak Sound Like?

An exhaust leak can often be identified by a distinctive sound. Some common sounds that may indicate an exhaust leak include the following.

  1. A loud, rumbling or booming noise that gets louder when the engine is revved.

  2. A hissing or whistling noise that becomes more pronounced when the engine is under load.

  3. A ticking or clicking noise that increases in frequency as the engine speed increases.

  4. A metallic rattling noise that occurs when the engine is idling or running at low speeds.

It is important to note that an exhaust leak can sometimes be difficult to detect, especially if it's small or located in a hard-to-reach area. In some cases, a mechanic may need to use specialized equipment to locate the source of the leak.

Is It Safe to Drive With an Exhaust Leak?

A car will usually run with an exhaust leak, but this does not make it safe to drive.

Even though a car will usually run fine, if you are aware that your vehicle has an exhaust leak, you shouldn't drive due to the risk of carbon monoxide and other exhaust fumes entering the cabin of the vehicle. If you do drive, always open your windows.

Carbon monoxide poisoning is not something to be laughed at, even though increased noise, vibrations, and reduced fuel efficiency may just be minor annoyances.

The car's interior may make you think that you are protected from harmful exhaust fumes, but it is not airtight, enabling carbon monoxide to seep in and have a hard time getting out.

Additionally, you can have an exhaust leaking close to the air intake for your cabin filter, providing a direct path for exhaust fumes to enter your car.

Headaches, fatigue, and disorientation brought on by exhaust fumes might all result in an accident. Leaving carbon monoxide poisoning untreated can be fatal.

Take your car as soon as you can to a car repair or exhaust shop if you notice any of the above signs, especially if you can smell exhaust fumes within the cabin.

If you suspect an exhaust leak, it is best to avoid driving with it; but, if you must, always drive with your windows open.

Will an Exhaust Leak Ruin or Damage an Engine?

It's unlikely an exhaust leak will damage an engine but in some situations it could cause problems which may lead to engine damage, such as the ECU setting the wrong air/fuel ratio caused by the leaking exhaust affecting oxygen sensors.

Your vehicle may also misfire if it has an exhaust leak, this could potentially lead to engine engine.

Due to the increased risk of engine damage, it's recommended to avoid driving the vehicle or running an engine if it it has an exhaust system leak.

How to Fix an Exhaust Leak

A leak brought on by a crack or hole in your exhaust system will be difficult to fix on your own. It may be possible to replace simply a section of the pipe or exhaust component by separating the two close connections and replacing the piece of exhaust.

However, because of rusty connections and bolts, this method is often expensive and difficult.

A good temporary solution is to use an exhaust leak repair product. The next best course of action in this situation is to bring your vehicle to a repair shop so that a new piece of pipe or part can be welded in to guarantee that your exhaust system is leak-free.

Exhaust leaks could be very dangerous since they allow exhaust fumes to enter the inside of your car. Exhaust emissions are particularly bad for your health in addition to being bad for the environment.

You should fix an exhaust leak before driving your vehicle.


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