What Is an Exhaust Leak?

An exhaust leak can negatively impact car performance.

An exhaust system expels burnt gases away from a car, reduces noise and air pollution and increases engine power. An exhaust system can develop leaks or places in an exhaust system where exhaust, or burnt gas, escapes.

Symptoms

A car with leaking exhaust rattles and shakes when idling. Ticking, popping noises or a loud roaring sound from the engine can also indicate an exhaust leak. A gas smell from within the vehicle cabin may also indicate an exhaust leak. Black soot on the exhaust tailpipe typically indicates a buildup of carbon, which may be a symptom of leaking exhaust.

Causes

Exhaust leaks can be caused by a buildup of rust or physical damage to the undercarriage. Driving over a speed bump or curb can scrape the undercarriage and damage or puncture the exhaust pipe, causing a leak. Undercarriage damage can also impair the oxygen sensor, which can result in an exhaust leak. Condensation buildup in the muffler can lead to corrosion and leaking exhaust.

Diagnosis

If you suspect an exhaust leak, visually inspect the exhaust system for problems, like holes in the muffler, or cracked, damaged or missing parts. Replace any necessary parts to correct the exhaust leak or take your car to a licensed technician to perform a diagnostic check and make any necessary repairs.

References

• AA1Car: Troubleshoot Exhaust Noise & Leaks
• "Auto Upkeep: Basic Car Care, Maintenance, and Repair"; Michael E. Gray; 2007

Resources

• "How Cars Work"; Tom Newton; 1999