Symptoms
- Deep rumbling sound from the exhaust system
- Volume has noticeably increased over days, weeks, or months
- Often louder at idle and under acceleration
- May be paired with a slight vibration felt through the pedals or floor
Likely causes
- CommonProgressively rusting muffler or resonatorRust perforation typically starts small and worsens gradually, increasing noise over time.
- CommonSmall exhaust leak at a joint slowly worseningA minor leak can widen gradually due to ongoing vibration and heat cycling.
- PossibleLoosening exhaust clamp allowing an increasing gapA clamp that's slowly backing off lets more sound escape over time.
- PossibleCatalytic converter beginning to break down internallyInternal degradation can sometimes produce an increasing rumble along with reduced performance.
- PossibleMultiple small issues compounding (common on older exhaust systems)Aging systems often develop several minor leaks around the same time.
What to do
- Track how quickly the volume has been increasing, since a rapid change points to a bigger, more urgent issue than a slow one.
- Visually inspect the exhaust system for visible rust, especially at the muffler and resonator, which are common failure points.
- Check exhaust clamps and joints for any visible gaps or looseness.
- Have a mechanic inspect the full exhaust system on a lift, since a progressive rumble often has more than one contributing spot by the time it's noticeable.
- Consider whether fuel economy or power has also changed, which could point toward a catalytic converter issue rather than just a leak.
- Get a worsening rumble addressed before it becomes a full-blown loud exhaust, since early leaks are often cheaper and easier to repair.
- Avoid extended driving with a significantly leaking exhaust, since fumes can potentially enter the cabin, especially with recirculated air off.
- Have a muffler shop weld or clamp-repair a leak, or replace the affected section as needed.
Tools and parts
- Flashlight
Exhaust pipe section, muffler, or clampSearch: “exhaust pipe or muffler for [year make model]”
When to call a pro
A rumble that's steadily getting louder should be inspected by a muffler or exhaust shop before it progresses into a major leak.
Safety
Use caution
A leaking exhaust can let fumes enter the cabin; drive with fresh outside air circulation rather than recirculated air until it's repaired, and get it inspected promptly.