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How to Find an Exhaust Leak (Step-by-Step)

Updated: Jan 8

Finding an exhaust leak can be a frustrating task, but it is essential to fix any leaks as they can be dangerous and reduce the performance of your vehicle. An exhaust leak can cause toxic fumes to enter the cabin, leading to health issues for the occupants.


In this article, we will discuss two methods for finding exhaust leaks: the soapy water method and the smoke machine method. We will also go over the most common places for exhaust leaks to occur and provide step-by-step instructions on how to find an exhaust leak.

 

Table of Contents:


a mechanic under a car inspecting the exhaust system for any exhaust leaks

Methods of Finding an Exhaust Leak

  • Soapy water method: This method involves using a solution of water and dish soap to locate the source of the exhaust leak. Bubbles will form at the location of the leak when the soapy water is applied.

  • Smoke machine method: This method involves using a smoke machine, which is a device that pumps smoke into the exhaust system. The smoke will escape from any holes or cracks, making it easy to locate the source of the leak.


You can use either method to find an exhaust leak, the soapy water method works great on a budget.


Where Are the Most Common Exhaust Leaks?

Exhaust leaks are most commonly found at the following locations.


  • Exhaust manifold: The exhaust manifold is the part of the exhaust system that collects exhaust gases from the engine's cylinders and directs them into the exhaust pipe. An exhaust manifold leak can be caused by a crack in the manifold or a loose connection.

  • Exhaust pipes: Exhaust pipes can become damaged due to corrosion or physical damage, resulting in an exhaust leak.

  • Exhaust muffler: The muffler is responsible for reducing noise produced by the exhaust gases. Muffler leaks can be caused by a hole in the muffler or a loose connection.

  • Catalytic converter: The catalytic converter is a vital part of the exhaust system that reduces harmful emissions. A catalytic converter can become damaged and start to leak exhaust gases.


How to Find an Exhaust Leak (Soapy Water Method)

  1. Best done with two people: It is helpful to have a second person assisting you with this process as they can help you locate the source of the leak more efficiently.

  2. Prepare the vehicle: Before starting the process, make sure the vehicle is in a stable and secure location. If you need to jack up the vehicle, make sure to use proper jacking points and use jack stands to support the vehicle.

  3. Jack up your vehicle safely: Use a hydraulic floor jack to lift the vehicle off the ground. Make sure to follow the manufacturer's instructions and use caution when lifting the vehicle.

  4. Turn ignition on but make sure the wheels don't move: Start the vehicle's engine and put the gearbox into park mode or neutral to prevent the wheels from turning.

  5. Put heavy duty temperature resistant gloves on: Exhaust pipes and manifolds can get very hot, so it is essential to protect your hands with heavy-duty gloves.

  6. Put a rag in the exhaust tip to create slight back pressure in the exhaust system: This will help to create a better seal and produce back pressure and make it easier to locate the source of the leak.

  7. Listen for hissing, whistling, or tapping sounds: As you listen for the sound of the leak, you may need to apply some throttle to the engine to increase the pressure in the exhaust system.

  8. Spray soapy water on the area you think is leaking: Slowly and carefully spray the soapy water solution on the suspected area of the leak. Be sure to cover all areas of the exhaust system where you think it may be leaking.

  9. If bubbles appear in the soapy water you have found an exhaust leak: If you see bubbles forming in the soapy water, it means you have found the source of the exhaust leak. Make a note of the location and check for any more leaks.


How to Find an Exhaust Leak (Smoke Machine Method)

  1. Best done with two people: As with the soapy water method, it is helpful to have a second person assisting you with this process.

  2. Prepare the vehicle: Make sure the vehicle is in a stable and secure location before starting the process. If you need to jack up the vehicle, make sure to use proper jacking points and use jack stands to support the vehicle.

  3. Jack up your vehicle safely: Use a hydraulic floor jack to lift the vehicle off the ground. Make sure to follow the manufacturer's instructions and use caution when lifting the vehicle.

  4. Put a smoke machine nozzle in the exhaust tip and tape it around the exhaust tip: Follow the manufacturer's instructions for using the smoke machine. Insert the nozzle into the exhaust tip and secure it with tape to create a tight seal.

  5. Look for any smoke being emitted from the exhaust pipes: As the smoke is pumped into the exhaust system, keep an eye out for any smoke escaping from the pipes. This will indicate the location of the exhaust leak.

  6. If smoke appears somewhere along the exhaust you have found an exhaust leak: If you see smoke escaping from the exhaust pipes, it means you have found the source of the exhaust leak. Make a note of the location and proceed to the next step.


Conclusion

Finding an exhaust leak can be a challenging task, but it is essential to fix any exhaust leaks as they can be dangerous and reduce the performance of your vehicle.


By following the steps outlined in this article, you can use either the soapy water method or the smoke machine method to find an exhaust leak and get your vehicle running safely and efficiently.

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