Car Suddenly Louder Than Normal? How to Find the Exhaust Problem

Reviewed 2026-11-03. Checked against the sources listed below. This is general information, not a substitute for a mechanic's inspection.

Quick answer

A car that is suddenly much louder usually has an exhaust leak: a rust hole, a split seam, a failed flex pipe or a joint that has come apart. Where the noise comes from tells you which part to check first. If you can also smell exhaust inside the car, treat it as urgent.

Start with where the noise is

Loudest at	What it often is	What to look for
Under the hood, ticking when cold	Manifold or gasket leak	Burned paint, soot near the engine
Under the front floor, rumble on acceleration	Flex pipe	Frayed braid, black soot
Under the middle of the car	Pipe joint or a rusted pipe	Soot, rust, a pipe that gives when squeezed
At the back	Muffler or tailpipe	Rust holes, split seams, a hanging pipe

Diagram of a car exhaust system from the engine to the tailpipe: exhaust manifold, flex pipe, oxygen sensors, catalytic converter, resonator, muffler, hangers and tailpipe — Trace the system from the engine to the tailpipe.

Did something just happen?

Hit a pothole, curb or road debris? Look for a crushed pipe, a loose joint or a broken hanger.
Heard a clunk, then the noise? A hanger or joint may have let go, and the pipe may be hanging low.
Louder after cold or wet weather? Rust can finally break through after working on a muffler or pipe for years.
Recent exhaust work? Check the joints that were touched. A gasket may not have seated.

Check it safely

Park on flat ground with the parking brake on. Let the exhaust cool.
Look under the car from the front to the back for soot, holes and low-hanging parts. If you need to go under, use proper stands, never a jack alone.
Start the engine outdoors, never in a closed garage, and listen for the spot where the noise is loudest.
Keep your hands away from hot metal and the tailpipe.

Can you keep driving?

A hole near the back is often mostly a noise problem at first, but do not leave it. Stop driving and get it fixed if:

You smell exhaust inside the car
Anyone feels a headache, dizziness or nausea
A pipe is hanging or dragging
The check engine light is flashing

Carbon monoxide has no color or smell, so a lack of smell does not prove the cabin is safe. CDC lists headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion as the most common symptoms.