Locating Diagnosing Exhaust Leaks
Whether it is a soft "chuff-chuff-chuffing" or a loud roar it can often be obvious that your vehicle has an exhaust leak. While an exhaust leak doesn't impact vehicle performance it is critical that you take care of any leaks that do occur in your exhaust system.
The exhaust system of your car is an important safety feature. Designed to direct exhaust gasses away from the passenger compartment, a leak can be very dangerous, even deadly. Older, rusting exhaust components are a very common cause of leaks but they can also occur from scraping on high spots or from debris thrown up underneath the vehicle. Fortunately it is quite easy to diagnose such a leak without any expensive tools.
The first thing to do to find an exhaust leak is to simply listen. By leaning below the bottom of the vehicle you can often hear where a leak is to begin to pinpoint the location. Without even lifting the vehicle you can usually tell if the leak is in the front or the back, on the right or the left. You should also check under the hood to see if you have a loose or cracked exhaust manifold.
Once you have an idea of the general location of the leak you can lift the vehicle onto ramps or jack stands to get under the vehicle and find the exact location. Always observe proper safety precautions when working under a vehicle and never get underneath a car supported by a jack. Also be certain to set your parking brake and place blocks in front of and behind the wheels that are left on the ground.
Under the vehicle, with the engine running and the transmission in park or neutral, look and listen for where the leak is. If you can't readily find the leak there are a couple of things you can do to help. First, you can have an assistant block the tailpipe with a rag. This will force more of the exhaust gasses out through the location of the leak to make it more obvious, and you might even see some soot blowing through. Another thing you can do is fashion a "stethoscope" using a bit of tubing, or even a short length of garden hose. By holding one end near your ear and moving the other along the exhaust you will likely be able to find the exact spot from where the noise is coming.
Once you have identified the leak you can then decide what you need to do to repair it. If it is a small leak from a pinhole or a loose clamp you may be able to fashion a repair on your own. Pinhole leaks can be repaired with patch materials available from any auto parts stores. Loose clamps may simply be able to be tightened. Even large parts of the exhaust system such as tubes or mufflers can often be replaced by simply removing the old parts and clamping in replacements.
