Most car manufacturers design their exhausts to not be loud, and in fact, they are made so that they should suppress noise coming into the car. But, over time your exhaust can get noisier, and in most cases, it will be due to a leak.

Trying to find where that leak coming from is actually surprisingly easy, even if you are not mechanically-minded. You can certainly learn how to make your car exhaust quieter and attempt to fix the noise yourself.

If there isn’t a leak, then it’s probably just a case of personal preference to the type of noise that you consider to be annoying. If the factory-fitted exhaust has no leaks, and you still want to make it quieter, then you’re going to have to get a new muffler fitted. I am not going to tell you how to do that here.

But what I will do instead, and assuming that you do have a leak, is take you through a cheap and easy process to make your car exhaust quieter with some noise reduction techniques. These simple and cheap methods will help you to silence your exhaust, so that it should be quieter both inside and outside of the car. These methods will only take a couple of hours to implement, and should cost no more than $20.

You don’t need to be a mechanic do to any of this, it honestly is that easy and cheap.

Step 1: Identify Where the Leak is Coming From

The first thing you will need to do is park up your car on a flat and firm surface. Don’t do this on an incline or on grass. 

Once the exhaust has cooled down, jack your car up securely. 

Assuming everything is safe and secure, you can get under the car to examine the exhaust.

If you already know where the leak is, take a look for any signs of damage. If you don’t know where the noisy leak is, you will need to start at the front of your car, and work your way to the rear, inspecting as you go.

Things to look out for include rust, punctures, cracks, damage, holes, or anything that looks out of place. The main cause of an exhaust leak will typically be a patch of rust.

If you can’t find a leak, start the engine up. A leak should be obvious now as you will see exhaust smoke coming from an area of the car’s exhaust pipe other than from the rear end.

Step 2: Fixing the Exhaust Leak

If you’re lucky, the leak will be small enough to be repaired cheaply by yourself with some cheap items I will come onto in a moment.

Generally speaking, if the entire exhaust is covered in rust, you are going to have to have it replaced entirely by a car workshop and mechanic.

However, if you are just seeing small holes and leaks on an otherwise in good shape exhaust, you should be able to patch things up yourself to fix the leak and make it quieter.

The cheapest way to fix those leaks, leading to a quieter car exhaust is to use patches or an epoxy.

  • Small leaks – you can repair them using exhaust tape (view on Amazon) or repair epoxy (view on Amazon)
  • Larger leaks – you can patch them up with a special kit plus the epoxy to seal it up

The Tape and Epoxy Method for Small Leaks

It’s really simple.

Firstly, clean up the area where you are going to be fixing so it’s free of debris, dirt, and rust. A wire brush is sometimes the best thing to use for this.

All you do is apply some exhaust tape over the leak. Let that stick, and then mix up the special epoxy to seal the tape. You can put the epoxy all over the tape, but the most important consideration is to ensure that there are no gaps on the sides of the tape where exhaust fumes can escape.

Leave everything to dry and settle for a couple of hours, and then repeat the checking procedure with the engine running.

The Patching Method for Larger Leaks

This takes a little more work, as you will need to figure out how large a patch you need to use. You can buy special exhaust patch kits (see some on Amazon) for this. It will not work if the leak is larger than 3 inches – if it’s that big, you will need to have that section of the exhaust replaced completely.

Before you apply any patching though, make sure you clean up the affected area so that it’s free of debris, rust, and dirt. Use a wire brush again for this.

Once you have cleaned the leak area up, you should cut a patch up that is large enough to leave about half an inch as an overlap to any sides of the leak in the exhaust.

Next, mix up the epoxy and apply that all around the leak and edges. Once that has been applied you can then stick the patch on. The epoxy should help to keep the patch stuck on but press down on it and keep holding until it’s firmly in place.

Once it’s stuck on, apply more epoxy over and around the patch area, making sure to seal the sides of the patch so no exhaust fumes can escape.

Now leave if for a couple of hours to dry well enough, and then perform a check test on it to see if you see any exhaust fumes escaping. 

How to Make Your Exhaust Quieter Inside the Car 

But what about inside your car?

Once you have completed the steps described above to make the car exhaust quieter, there are also some extra steps you can take to address the noise that’s coming inside of the car.

I have written extensively on the Soundproof Guides website about how to make your car quieter inside which tells you what you need to do and buy.

If you don’t have the time to read that and want some quick guidance on how to make your exhaust quieter inside your car, then here’s what you should do.

Cheap & Easy: Fit Sound Deadening Foam Inside the Car

Most noise from your exhaust will come up through the bottom of your car. Thankfully there is a product that can help to muffle this type of noise, which is called sound deadening foam.

My recommended foam is called FatMat – you can view the latest prices on Amazon. It’s usually very cheap and you will have to cut it to size to fit into the floor wells of your car.

In around 45 minutes or so you can have it installed underneath your floor mats. Here is a real simple overview on what to do to reduce exhaust noise inside your car:

  1. Remove front floor mats
  2. Cut FatMat to fit the space
  3. Lay it in the space (it has adhesive so it will stick)
  4. Place original floor mats back on top

And that’s it.

By using these methods you could realistically spend less than $100 and make your car exhaust much quieter – not only for you inside the car, but also for your neighbors!