How to Make an Engine Quieter: Top 5 Methods!

When you first buy a car (or any vehicle for that matter) the engine will be at its quietest state. But after a few years the wear and tear can make it considerably noisier. As one forum member said:

…exhaust shields begin to rattle or fall off entirely…the valvetrain gets noisier…pulleys begin to squeak…all the little things that add up to a noisier engine after the first 100K.

Besides quieting an older engine, there are ways to make even a new engine quieter by surrounding it with noise-absorbing materials. In this article I’ll share the simplest and most affordable ways to make an engine quieter.

1. Switch from regular to synthetic oil

Many noisy engine owners have found this simple method to work well. Synthetic oil will clean, cool and lubricate an engine more effectively  and as a result reduce the noise. Even if an engine is pretty old and you’ve used only regular oil, making this switch can make a world of difference. Just keep in mind that it may take a month or sometimes a few months for the new oil to make an impact. I personally use the Mobil 1 Synthetic Motor Oil (affiliate link) and I’ve never had issues with excessive car noise.

2. Change oil often and use bypass engine oil filters

Oil should be changed every 90 days or so. Some mechanics and car owners also recommend super bypassing (i.e. using external oil filters) to keep an engine quiet, especially over 250,000 miles or so. If you’re not sure what product would suit your vehicle, filter the products by inserting your vehicle specifications on Amazon (aff link) to get the best recommendation.

3. Use an additive to improve engine performance and reduce wear on vital parts

Additives are a great way to extend engine life, increase gas mileage and improve performance overall. By doing so, it will also reduce noise. Zmax (aff link) is a great multi-purpose additive, and it’s quite affordable.

4. Soundproof the engine compartment and cabin

Improving the engine’s performance can work well, but if you want better results also consider soundproofing the engine compartment and your car cabin. Some cars simply have lousy sound insulation that needs to be improved with additional soundproofing products.

Thankfully, there are many sound deadening mats designed specifically for cars and similar vehicles. Dynamat (aff link) is the most well known of the bunch an has the greatest track record. It’s also the priciest. If you want to lower your cost substantially, consider getting Noico or FatMat.

These mats have a self-adhesive side, so installing them on any clean surface is easy. Simply place it on the surface and it’ll stick! If it doesn’t stick immediately, apply some extra pressure with your hand or with a roller. These mats are designed for high-temperature settings so they can be used in the engine compartment, car cabin or any other part of the vehicle. They absorb much of the air-borne and some of the impact noise coming from the source. So if you’re also bothered by road noise, consider inserting these mats into the car doors and on the cabin floor as well.

I’ve mentioned these three products because I know many people who’ve had success with them. There are similar alternatives on the market as well such as KillMat for example, but these use basically the same material so there isn’t much of a difference whichever one you go with as long as the thickness is about the same.

There are also sound deadening sprays (foam) which can be a good alternative for hard to reach surfaces. For example inside car doors. But they’re also messy and look ugly in the open so I would use them only when it’s necessary and stick with the mats. But you can check my comparison article to learn more about this option: sound deadening sprays vs mats.

5. Install an exhaust muffler, resonator and/or silencer

Sometimes the noise is not coming directly from a problem in the engine. The reason could be that you just have a powerful engine and your exhaust system could use an upgrade to make it quieter. There are three great options for doing this, if you haven’t already of course:

1. Exhaust muffler: A muffler is designed like a small labyrinth. Gas has to pass through various passages and resonating chambers before it can get out through the exhaust. Through this process sound pressure gets reduced by a fair bit. Mufflers are usually lined up with fiberglass insulation, a material used in many soundproofing products for reducing airborne and impact noise. This is a very popular device for lowering noise on any sort of engine, whether it’s a vehicle, generator etc.
2. Exhaust resonator: Resonators are often mixed in with mufflers. But there’s a difference. A resonator is a straight pipe, not as wide as a muffler. Instead of making sound waves pass through a labyrinth, it makes them crash against one another. While a muffler reduces all sound, a resonator is very effective for the buzzing and droning noise. It also decreases engine back pressure, and therefore increases engine performance.
3. Universal silencer: This is very effective and affordable! Simply insert this universal silencer (aff link) in your exhaust (from the outside, without taking off any parts) and you’re good to go. Works like a charm.

To learn more about quieting your engine with these methods check out my more in-depth article (how to videos included).

Final Word: How to Make an Engine Quieter

Engine noise is unavoidable. But you don’t have to be a victim of excessive noise. Just like a digestive system that is overwhelmed can create bloating and well.. noise… so can an engine that isn’t treated with enough attention. So keeping the engine in top shape by using synthetic oil and an additive is a great start. If you want to cozy up to your engine even more, adding a bypass engine filter to the mix will do the trick.

Sometimes the engine is still too loud even when these improvements are made. In that case applying sound deadening mats to the most sensitive areas, primarily the car cabin and the engine compartment will provide even better results. Also consider investing in a muffler, resonator and/or universal silencer. These can make a HUGE difference if the majority of the noise is coming from the exhaust. Hope this helps!