How to install DIY under hood insulation [2021]

After owning a car for a while you will begin to notice that some sounds will start to get louder. 

One sound that seems to get louder over time is the sound of the engine. 

While it’s perfectly normal to think that there might be something wrong with the engine, oftentimes it may be because of worn or damaged car hood insulation.

A hood liner or insulation may become worn or damaged over type while some cars may not even come with this component at all. 

If that’s the case, don’t worry as you can make your own

In this article, we’ll go through the process of how to create and install your DIY under hood insulation.

Product

Features

Price

Noico 80 mil (2 mm) 36 sqft (3.4 sqm) car Sound deadening...
  • Audio insulation
  • 1.5x thicker
  • Self-adhesive
Dynamat 11905 Hoodliner 32' x 54' x 3/4' Thick Self-Adhesive...
  • 75″ acoustic sound soaker foam
  • oil and water-resistant
  • provides 97% heat reflection
FatMat Hood-Liner 34' x 54' x 3/4' Thick Self-Adhesive...
  • acoustic/thermal insulation
  • Peel and stick application
  • Foam material

DIY under hood insulation

Hood insulation is usually made from a thin layer of material that consists of some sound deadening properties.

It is used in cars and performs two very important tasks. 

The first task is to dampen the noise of the engine so that those in the car and those in close vicinity would not be disturbed. 

The other function it serves is to make the paint on the hood last longer. 

While you can buy hood insulation you can create and install your own DIY under hood insulation.

This way you can customize the appearance and functionality to suit your preferences. 

Why use under hood insulation?

hood insulation

There are many reasons why you should insulate the hood on your vehicle if your vehicle doesn’t come with any.

It is very easy to check to see if your car has under hood insulation or not.

Simply lift the hood and if you see a layer of fabric or foam on the inside, then you do have hood insulation.

These premade hood insulators help to prevent the metal parts from overheating. 

If you don’t see any, then you should install some.

Here are a few of the benefits of hood insulation.

Absorbs vibrations

Sound insulation absorbs most of the vibrations that come from the engine compartment. 

It stops those vibrations so that they are unable to travel through the body of the car and into the cabin. 

This makes for a quieter and more peaceful ride. 

Reduce the chances of the hood overheating 

Insulation can help with keeping temperatures in the engine compartment constant. 

The difference may not be anything too drastic but many people have claimed that their hoods stopped overheating because they used hood insulation. 

Prevent paint on the hood from peeling 

Temperatures under the hood can get very high which can damage the paint on the top of the hood easily. 

An insulating layer may prevent the paint from peeling off and make your paint job last longer. 

Stop fire from spreading 

In some instances, insulation can help to stop a fire from spreading. 

If your engine catches fire, the hood insulation can help to stop it from spreading to the other parts of the car. 

In some cases, it may even put it out which would minimize damage and can save your life. 

Buying criteria for choosing the right under hood insulating material

When deciding on which material to use as your under hood insulation replacement, you have two main options. 

One is to use sound deadening mats and the other is to use hood liners. 

There isn’t much of a difference between the two other than the insulation they prioritize. 

Sound dampening mats, for example, focus more on acoustic insulation and have a level of thermal insulation as well. 

Hood liners, on the other end, focus solely on thermal insulation. 

They may or may not contain acoustic insulation properties and this all depends on the brand. 

Here are a few things to look for to ensure that you have the right product to meet your needs. 

Thickness 

A thicker mat usually provides better acoustic insulation than a thinner one. 

Ease of use 

Look for hood insulation materials that come with self-adhesive backing. 

This can make installation that much easier. 

Cost 

You will find that the more expensive the insulation material is, the better it performs.

This is because the cost can have an impact on the quality. 

However, you may be able to find pocket-friendly options that perform well. 

Mass 

Mass and thickness work in a similar manner meaning that the more mass the material has, the better the insulating properties. 

Do keep in mind that a mass-heavy mat does not need to be thick. 

The amount you need

There is no fixed amount of sound deadening material you’ll need for your hood insulation. 

This is because the amount you need will depend on the size of your hood panel. 

That being said, you probably won’t go wrong if you get a 60”x 60” sheet. 

A sheet of this size should allow you to cut according to the shape of almost any hood. 

In some cases, you may find that people may not want to insulate the entire hood. 

instead, they’ll insulate a certain area around the engine itself. 

However, it is best to insulate the entire hood as insulating just one part can still allow some of the noise and vibrations that travel through the car’s body and get to you. 

On the other hand, if you still decide to insulate only a part of your hood then measure that specific area to determine how much material you’ll need. 

When you have those numbers down, add an extra 5 inches to each value. 

This allows you to compensate for the curves of the hood as well as giving yourself some room for error 

Best under hood insulation material

There are many different types of under-hood insulation material to choose from. 

You can either use one of these or combine them to ensure that you are fully protected. 

Sound deadening mats 

Many people turn to sound deadening mats to provide them with sound insulation as well as thermal insulation. 

This is because sound deadening mats are one of the simplest and most practical materials for any kind of DIY under hood insulation. 

Read more on sound deadening materials or check out this sound deadening mat below.

Noico 80 mil car Sound deadening mat

Noico 80 mil (2 mm) 36 sqft (3.4 sqm) car Sound deadening...

  • Audio insulation
  • 1.5x thicker
  • Self-adhesive

If you’re looking for a high-quality sound deadening material then Noico Sound-Deadening Mat should be your number one choice.

This is because this product meets all the important criteria when it comes to soundproofing.

Not only is it soundproof but it costs way less when compared to the other expensive options.

Moreover, it works with virtually any surface which means that if you end up with excess after you’ve finished insulating your hood, you can also cover your doors, floor and roof.

This mat is very easy to install since it features self-adhesive backing.

Installation is also made easier with the special embossing which helps to tell you whether it’s properly set up or not.

Ultimately, you want the foil completely smooth and once it’s smooth then you’ll know that it is set up correctly.

While the mat does have some thickness to it and is full-weighted, you can add more mass to whatever surface you’re using it on.

As we mentioned before, more mass equals less noise coming through that very surface.

Noico 80 mil (2 mm) 36 sqft (3.4 sqm) car Sound deadening…
  • The cost effective 80 mil automotive butyl and foil sound deadening! You are not just buying an…
  • Now the material is 1,5 times thicker that will get you 1,5 times more effective insulation. Noico…
  • Automotive self-adhesive insulation consists of butyl. Noico sound deadening has a total weight of…

Hood Liner 

While some people prefer sound deadening mats others will opt for a hood liner. 

A high-quality hood liner provides you with great thermal insulation and may also provide sound insulation. 

These products are specifically made to insulate the hood of your car. 

Hood liners usually feature a self-adhesive backing and come in a standard size that can be cut into the shape of your vehicle’s hood. 

One major difference and advantage of hood liners over sound deadening mats is that hood liners are usually thicker to provide sufficient thermal insulation.

However, this can vary depending on the manufacturer. 

Dynamat Hood liner

Dynamat 11905 Hoodliner 32' x 54' x 3/4' Thick Self-Adhesive...

  • 75″ acoustic sound soaker foam
  • oil and water-resistant
  • provides 97% heat reflection

This hood liner comes from a well-known car insulation manufacturer, Dynamat.

You can find a variety of products on the market from this manufacturer.

This product is of high quality and can significantly reduce the amount of sound coming from your engine.

Although it is very dense, installation is still a breeze with its high-tack pressure-sensitive self-adhesive backing.

All you have to do is ensure that you take correct measurements before cutting the material.

You’ll find that most hoods aren’t exactly flat and they may have concaves and convex surfaces which can make cutting the material a bit complex.

Just stick with your measurements and you should be fine.

When applied correctly, this dynamite hood liner stays securely in place due to its high tack adhesive and the fact that it is both oil and water-resistant.

The Dynamat hood liner also has a pretty shiny metallic appearance with a combination of open and closed cells to absorb sound waves and dissipate them.

Sale
Dynamat 11905 Hoodliner 32″ x 54″ x 3/4″ Thick Self-Adhesive…
  • Country of origin : United States
  • Package Dimensions : 36″ L x 8″ W x 8″ H
  • Package weight : 5 pounds

Fat Mat Hood Liner

FatMat Hood-Liner 34' x 54' x 3/4' Thick Self-Adhesive...

  • acoustic/thermal insulation
  • Peel and stick application
  • Foam material

The Fat Mat hood liner is kind of similar to the Dynamat hood liner.

This particular product is made up of acoustic foam that is reinforced with aluminum foil which allows it to have both sound and thermal insulation properties.

It also has some additional heat-resistant features which help it to protect the paint on your hood from the heat coming off of your engine.

Meanwhile, the acoustic foam properties will reduce the level of noise-induced vibrations coming from the engine.

Installing this product is easy as it comes with a simple peel-and-stick application process and as long as it’s installed correctly you should notice instant results.

Read this noico vs dynamat vs hushmat vs fatmat guide to understand how each of them works.

FatMat Hood-Liner 34″ x 54″ x 3/4″ Thick Self-Adhesive…
  • Engine Compartment Acoustic/Thermal Insulation
  • Line Underside of Hood to Reduce Engine Noise! Acoustical Foam Designed for Maximum Sound Absorption
  • Reduce Hood Heat Absorption! Black Urethane Face Absorbs and Disperses Heat Evenly Without…

Sound deadeners and hood liners

As we said before you can choose one of these materials or you can combine them. 

Combining them would probably be a good idea since you will be doubling up on the sound insulation and thermal insulation. 

However, you may be wondering how you install a sound deadener and a hood liner together. 

You do not need to worry about that since the process to do this isn’t too difficult. 

Most of these products come with self-adhesive backing and are DIY friendly. 

To get started, you will need to cut both of them into the appropriate shape. 

Next, remove the disposable backing from the sound deadener and place it on the hood. 

After that, install the hood liner on top of the sound deadener which now acts as the base. 

Once completed, you will now enjoy the benefits from the soundproofing and thermal qualities of both products. 

Remember that these products go inside the hood, so if you do not pick any of our choices, it is necessary to pick products that are made from heat-resistant materials. 

Failure to do so will allow the heat that is coming from the engine to damage the installation and may even put you in danger. 

How to install custom under hood insulation

car-hood-insulation

To install a custom under hood liner, simply follow these basic steps below or check out the video. 

Prepare the tools

The main tool you’ll need is something to cut the material to the shape of your hood.

This can either be a pair of heavy-duty scissors or a utility knife. 

Most times these materials are self-adhesive so you won’t be needing any glue or adhesive. 

You can use a roller if you want as it will help to make sure that the liner is flat and even. 

Remove existing hood insulation. 

If your existing hood insulation is worn or damaged, you will need to remove it before installing the new one. 

Sometimes removing the existing hood insulation can give you a hard time.

If it does, you can use a flat knife to lift and peel the corners. 

After that, you can proceed to remove it by hand but take your time to not damage the paint. 

Clean off any grime or dirt 

Take a peek at the inside of the hood panel and clean off any grime or dirt that you see. 

The hood needs to be perfectly clean so that the adhesive can function as it should and grip properly. 

Depending on how dirty things are, you may need to use a degreaser to remove any oil buildup. 

Use the old insulation as a guide 

This step only works for those who had insulation installed before. 

After successfully removing the old installation, you can place it over the new liner material and use it as a guide.

Using scissors or a utility knife, cut out the shapes according to the outline.

Cut the insulation

If you don’t have old insulation to use as an outline, you will just have to cut the sheets into shapes that match the dips in your hood panel. 

After cutting shapes to match all the dips, you will then need to cut the rest of the material into strips which will be used to cover the convex borders between the dips. 

Peel and stick

To apply insulation to the inside of the hood panel you need to make sure that everything is cut the size. 

This is because once you attach the insulation to the hood panel it is going to be extremely hard to remove. 

If that does happen and you still manage to remove it, you’ll need to use a new piece of material since the other would have lost most of its adhesive properties

In the end, if you have any excess left behind you can use it and layer up for better results. 

Use a roller 

you can use a roller to ensure that there are no creases or folds once the installation has been applied. 

This will allow your installation to look smooth and neat and may even help the insulation stick better.

Tidy it up 

To make things look a little bit tidier,  use a utility knife to trim any overlaps or protruding pieces.

Product

Features

Price

Noico 80 mil (2 mm) 36 sqft (3.4 sqm) car Sound deadening...
  • Audio insulation
  • 1.5x thicker
  • Self-adhesive
Dynamat 11905 Hoodliner 32' x 54' x 3/4' Thick Self-Adhesive...
  • 75″ acoustic sound soaker foam
  • oil and water-resistant
  • provides 97% heat reflection
FatMat Hood-Liner 34' x 54' x 3/4' Thick Self-Adhesive...
  • acoustic/thermal insulation
  • Peel and stick application
  • Foam material

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