How to Find a Car Exhaust Leak

A crack in a car exhaust system is not just a minor inconvenience.  Depending on the severity of the leak, you could be breathing in noxious fumes while driving or even causing additional wear and tear on any components located near the leak.  Rather than run the risk, take some time to inspect the exhaust system from one end to the other, then call in the professionals to get the problem repaired.

A car exhaust leak is not something to be taken lightly.  Typically, the leak not only means that exhaust is escaping before being expelled via the tailpipe, but also that the leak may be located near some other essential component in the car design.  Over time, that simple leak can lead to more serious mechanical issues that will be very costly to repair.  For this reason, addressing a potential exhaust leak early on is a very wise move.

1. Begin the search for an exhaust leak when the car engine and other components are cool.  Early morning when the car has been setting overnight is a good time.  Position the car so that you have easy but safe access to the tailpipe and the underside of the vehicle, as well as the ability to raise the hood and look at what is happening around the engine.


2. Cover the tailpipe.  Since the idea is to discover where exhaust is being expelled other than out the end of the tail pipe, a simple cover will force the exhaust through any leaks along the tail pipe or even in the exhaust manifold and other portions of the system.


3. Start the engine.  Leaving the car in the park position, allow the engine to gradually warm up.  As the car runs, look for signs of exhaust escaping from around the engine or anywhere along the expanse of the exhaust system.  Do not touch the components with your bare hands, as the metal is likely to be very hot by the time the exhaust begins to escape. Note where you detect signs of leakage for reference later on.


4. Listen for the characteristic hiss that occurs when exhaust is escaping through a crack.  Keep in mind the crack may be anywhere along the expanse of the tail pipe or be in the exhaust manifold itself, especially with older cars that are still operating with the original manifold.


5. Call in the professionals.  Once you’ve spotted what you believe are cracks in the exhaust system, take the car to a mechanic.  Many repair shops can use computer technology to confirm your findings and possibly also identify points of weakness in the exhaust system that are not yet a problem, but could rupture into more cracks in the near future.  From there, you and the mechanic can settle on the best course of action to repair the leaks and get you back on the road.