How to Fix Your Noisy Exhaust System

Written by Shelley Cole on January 30, 2018

If you’ve got a classic muscle car on your hands, you’re probably in love with how it throatily roars when you hit the gas. And that engine, when opened up, is a sight of pure beauty. Sometimes though, we’re faced with having a wonderful classic on our hands that doesn’t sound as it should, it’s simply... loud.

The question, then, is “how should we go about fixing the exhaust system on a classic car?”

Thankfully, fixing a noisy exhaust system on a classic car isn’t that different from fixing an exhaust system on a more recent one. Exhaust systems, for the most part, have remained pretty static, save the catalytic converter and centre resonator developments.

If you’ve got a noisy system, there’s likely a hole or perforation somewhere along the exhaust pipe, the muffler or even the tailpipe. Even a pen-sized hole in the muffler will have a noticeable impact on the sound. Note: This is not to be confused with a “weep hole”. The weep hole is always in a precise location as it allows water to be evacuated from the muffler.

Our first step is to find the hole (i.e. the source of the sound). If the hole is visible, our work is infinitely simplified. We’ll simply need to change the perforated piece to bring back our proper sound. You’ll likely be able to do it yourself or with relatively minimal effort or cost-effectively at a local shop.

Smaller leaks though, are sometimes a little more difficult to locate but can be found performing what we refer to as the rag test, which can be seen here.

The only challenge you may encounter as a DIY'er is where dismantling the pieces to replace may be a little challenging or if the piece you're looking for, for whatever the reason, is no longer available on the market.

The latter situation is something we classic car owners are used to encountering, but always leaves the question to be answered. “Do I stay true to my car's roots with original pieces, or simple repair the issue with more recent and available options?”.

Either way you decide to go, the easier versions of this job are very much a DIY'er level job, but as always, we’ll suggest if you’re uncomfortable with any aspect of the job, or have trouble locating the leak or hole, look to your local classic car specialist or exhaust system professional to lend a hand.

Happy repairs!

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