Effects of Having a Hole In Your Muffler

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on June 17th, 2024

Reading Time: 4 minutes
Summary
  • The muffler is the part of your exhaust system that muffles the noise emitted by the exhaust of your engine. But over time, it’s prone to corrosion.
  • Holes that form because of corrosion or accidents are typically found on the part of the muffler nearest to the exhaust pipes.
  • Symptoms of a bad muffler include excessive noise, exhaust gases entering your cabin, and excessive exhaust escaping from your vehicle. If you suspect there’s a hole in your muffler or another area of your exhaust system, ask a certified mechanic to check your vehicle.

The muffler plays a vital role in your car’s exhaust system. Its main purpose, as its name implies, is to muffle the noise emitted by the exhaust of your engine. Over time, it may corrode and develop holes on its surface.

What Happens When You Have a Hole In Your Muffler?

You should definitely pay attention to holes and other anomalies that form on your muffler over time. Holes that form because of corrosion or accidents are typically found on the part of the muffler nearest to the exhaust pipes. Below are some of the effects of having a hole in your muffler:

Holes that form because of corrosion or accidents are typically found on the part of the muffler nearest to the exhaust pipes.

Excessive Noise

An unusual, loud, rumbling noise is the most noticeable sign that there’s a hole your muffler. The muffler’s primary purpose is to muffle or dampen the sounds coming from the engine. If the muffler is damaged, its effectiveness at keeping engine sounds to a minimum goes down drastically. As the muffler continues to degrade and the hole(s) get bigger, the noises may get even louder.

While it is possible for there to be leaks somewhere else along the exhaust system, in many cases, loud exhaust is usually caused by a damaged muffler.

Exhaust Gases Entering Your Cabin

This is the most dangerous effect of having a hole in your muffler. Holes along the exhaust system can cause harmful gases to seep into your passenger cabin. These gases include carbon monoxide. Carbon monoxide is a deadly, odorless, and colorless gas that’s produced by the incomplete burning of fuels.

If you’ve been exposed to high concentrations of it for an extended period of time, this gas can cause headaches, fatigue, nausea, dizziness, difficulty breathing, confusion, and even death.. Carbon monoxide is especially dangerous to small children and the elderly.

Because it’s odorless and colorless, you won’t know right away if you’ve been exposed to it until you start experiencing the symptoms. If you suspect that you’ve been exposed to carbon monoxide, roll down your windows immediately to let fresh air circulate through the cabin. Have your vehicle checked by a certified mechanic as soon as possible.

That being said, older vehicles or poorly maintained newer ones are more prone to produce CO (carbon monoxide) than vehicles built after the mid-80s mainly due to tightening emissions standards. Modern vehicles only produce CO2 and water, both of which are totally harmless. You might even notice how green the grass is right next to the road because CO2 from vehicle exhaust accelerates plant growth.

A hole in your muffler can allow emissions to freely enter the atmosphere and harm the environment.

Pollution

Aside from the uncomfortably loud noise and potentially lethal gases, a hole in your muffler can allow other emissions to freely enter the atmosphere and harm the environment. A hole in your exhaust can also make you fail emissions tests.

Of course, the muffler and/or resonator is typically after the catalytic converter(s), which means that any gas leaking from a hole in your muffler is no worse than the gasses coming out of the tailpipe.

Weep Holes

Mufflers are in a very hostile environment and have a difficult job, especially in road salt states where the whole underbody of the car becomes a study in rust formation. But water can gather in the muffler if there’s no way for it to drain.

Thus, many mufflers have a small hole located toward its rear called a weep hole, and it’s there for a very good reason.

But first, a bit of a chemistry refresher. Water is a byproduct of burning fuel. For each gallon of gasoline burned, approximately one gallon of water (in the form of steam/water vapor) is produced. The water vapor then condenses (or turns into liquid) on the cooler areas of the exhaust system (particularly in the muffler) until the vehicle is driven long enough to push the temperatures in the exhaust system past the boiling point of water (212°F/100°C).

Because water accumulates in the muffler, it needs to drain out somewhere to avoid corroding and damaging the rest of the exhaust system. This is why your muffler has a weep hole.

Can You Drive with a Hole in Your Muffler?

If you suspect that there’s a hole in your muffler or anywhere else in your exhaust system, you should immediately have it checked by a certified mechanic. Driving with a damaged muffler can put you and your loved ones at risk, so don’t take any chances.

Get a Replacement Muffler Delivered to Your Doorstep

Replace a holey muffler as early as you can before it causes problems. Otherwise, your vehicle will fail its next emissions test, or have other issues like strange noises caused by the exhaust gases escaping through the holes in the muffler’s walls. Fortunately, CarParts.com ships your replacement muffler to where you need it, helping you get your car back on the road.

CarParts.com delivers world-class car mufflers to your doorstep. We operate several warehouses in strategic locations across the US, ensuring fast delivery times. The nearest warehouse processes your order using the latest technology before shipping your new part to your address. If you live in the continental US and place your order before 12 p.m. ET, you can expect your replacement part to arrive within several business days. Furthermore, we guarantee the reliability and performance of our mufflers by exclusively sourcing our parts from trusted manufacturers. We ensure you get the biggest bang for your buck.

When you’re ready to purchase a replacement muffler, look no further than CarParts.com. Order one of our mufflers today and save on high-grade exhaust parts.

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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Published by
CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician
Tags: Muffler