How to Make a Muffler Quiet? – Pipe Down Your Noisy Exhaust Smartly

The ear-deafening exhaust sound only feels cool and justified on F1 race tracks or car-drifting arenas. Your regular street vehicles are far from it. In an average neighborhood, there’s nothing more triggering than roaring engine exhausts. In fact, some states have even banned overly noisy exhaust pipes.

If you are conscious of waking your neighbors when you cold-start the car in the morning or fear getting reported due to the noisy exhaust, it’s high time you make arrangements to silence the muffler. Unlike the standard notion, you can make a muffler quiet without undermining the car’s performance. We’ve shared the most widely applied methods and solutions to silence your muffler effectively.

Leaky holes, a loose resonator, or catalytic converter failure may cause your car muffler to be overly noisy. First, you need to seal the holes in the exhaust pipes to limit noise emission, then install a silencer to make the muffler quiet. Steel wool wads and exhaust wraps are also effective DIY methods to quieten an exhaust. If nothing works, you should replace the muffler altogether.

Why are Car Exhausts So Loud?

Car exhaust systems produce low-frequency sound waves with a high bass factor. Such sounds have a higher vibrational impact which is difficult to suppress and travels further than other high-pitched sounds. That’s the reason you can hear the engine revs of bass-boosted supercars from hundreds of meters away.

Talking about supercars, they have exclusively modified mufflers that produce the seductive engine growl most car enthusiasts love. Standard street-legal cars, on the other hand, come with muffled-down exhaust systems that don’t contribute much to noise pollution. But if your car sounds louder than usual, it probably indicates a malfunction. Here are a few possible reasons why your car exhaust is so noisy:

Leaky Holes

Normally, car exhausts generate low-frequency sounds indicating the proper functioning of the car. But if you hear a high-pitched noise from your car’s exhaust as you start accelerating, it highlights a potential flaw in the rear muffler – possibly a leaky hole.

Besides being a prevalent cause of noise pollution, holes in an exhaust muffler expel poisonous fumes that may seep into the car cabin. A higher concentration of untreated exhaust gases like carbon monoxide inside the car can have hazardous outcomes. So, be mindful and notice changes in the exhaust sounds before it’s too late.

Loose Resonator

A resonator does what a muffler does best – reducing the exhaust noise from the vehicle. It is installed beside the muffler on the exhaust assembly and helps silence the growling noise. In case of a loose-fitting with the assembly, the resonator may emit whining noise coupled with a loud clatter, sometimes too loud to ignore. This problem is rampant in old car models that have missed occasional maintenance checks.

Catalytic Converter Failure

Sometimes, the unusual sounds from the exhaust are directly linked to the catalytic converter. It is a vital component in a vehicle’s exhaust assembly that transforms toxic fumes from the engine into less-toxic gasses limiting the extent of air pollution.

However, an improper installation, loose heat shield, and functional failure of the catalytic converter result in a loud rattling noise from the exhaust. Cleaning the converter or mounting it tightly could minimize the noise. But, consider consulting a professional if the rattling doesn’t stop.

Loud Car Exhaust – 3 Ways to Make a Muffler Quiet

According to the latest noise pollution metrics, noise from a car exhaust must not exceed 72 dB, with a special crackdown against illegally modified car exhausts. Before your extensively loud exhaust gets you into any scrutiny by the authorities, start making preparations to muffle the noise.

Ask yourself the question; why is the car’s exhaust muffler so noisy? Whether the exhaust pipes are damaged and leaking or the valve lifters have gone loose, you must identify the cause of the unusual noise.

Mount the car on a trolley jack and inspect the base of your car for any hits and damages. Don’t forget to let the exhaust cool down before you initiate the inspection. Regardless of the reason, adopting the following methods will help you quiet the muffler.

Plug the Leak

Unnoticed rust and hits from the ground can form leaky holes in the exhaust pipe, which end up producing a loud whining noise. Even though mufflers often remain burning hot, mending the leaking holes is easy as long as you have the right materials. Unlike normal sealant that melts off or burns out when the muffler gets hot, get your hands on a heat-resistant epoxy for a better job.

In case of minor leaks and perforations, use the Gorilla Epoxy Stick to plug the holes. Upon drying, the innovative material turns solid as the metal itself, ensuring a sturdy and long-lasting finish. You can also top it off with Heat Harness Tape for advanced protection against abrasion and heat.

As for the larger leaks, the epoxy won’t settle well enough in the gap, which leads us to Muffler Putty. This powerful substance works well in sealing muffler joints and connections, offering a solid build within minutes. Nevertheless, scrub the surface of any rust and debris before applying the solution.

Install a Silencer

If you hear your exhaust sound well enough inside your car, the outside traffic is faring worse. While the mufflers are installed to soothe the exhaust volume even at accelerations, they often fail to quiet the exhaust to the required levels. Nonetheless, muffler silencers have proven quite effective in this regard.

Compared to a regular muffler, silencers exhibit small thinner perforations that make it difficult for sound to pass through, thus offering a silent exhaust emission. The slip-on silencer versions allow an easy and seamless installation. Here’s a stainless steel muffler silencer you may want to mount on your car’s exhaust. This universal exhaust silencer is compatible with a variety of car exhaust systems. But if you want to save up on the costs, you can custom craft a DIY silencer as well.

Replace the Muffler

If mending the leakages and scrubbing the rust doesn’t seem to quieten the muffler, this might be the time you look for replacements. With the endless variety of car mufflers, consult an auto expert to find the perfect fit for your car. Once you purchase the recommended muffler, mounting it onto your exhaust system isn’t a big deal.

If the bolts and nuts on the old muffler appear too rusty to budge, spray WD-40 fluid to un-jam the components. You may need to apply the solution several times before they loosen up. Now pull out the noisy muffler from the rubber mounts and replace it with the newer model. Make sure to apply sealant across the exhaust pipe so it won’t leak or budge anytime soon.

DIY Methods to Make a Car Muffler Quiet

As a DIY enthusiast, making a car muffler quiet might be one of those projects you can tackle yourself without paying extra for a professional’s time. Here are some practical DIY methods to silence a car muffler:

Add Baffles

Soundproofing a car’s exhaust with baffles can dramatically reduce muffler noise. Baffles use thick pads wrapped around the muffler, absorbing vibrational sound waves produced when exhaust gases are expelled. These vibrations are either canceled out, reflected off, or contribute to heat energy. The energy is then dissipated to the surroundings, making sure neither heat nor sound gets to you.

Use Exhaust Wraps

Exhaust wraps work the same way as baffles, except they are embossed throughout the exhaust pipes. Being made from a soft padded material such as fiberglass or aluminum foil, the wraps can effectively absorb high vibrational sound waves and disintegrate them into other forms of energy. The Fiberglass Exhaust Wrapping reduces the loud whine caused by the muffler into a low hum. You can also wrap both versions together to attain maximum noise reduction.

Implant Steel Wool Wad

While it may not help dissipate excessive noise permanently, embedding a wad of steel wool is a widely applied method to silence an exhaust muffler. Drill two small holes into the exhaust pipes a few inches from the muffler, and shove wads of steel wool deep into the holes. Use a thread or wire and insert it across the pipe to tighten the wool wads. With its soft and soaky texture, steel wool functions as an effective sound-deadening material.