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Noise Dampening How-To

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Some older cars and a lot of newer, lower cost cars have noise problems. Both types of vehicles have problems for the same basic reasons and it can really degrade from the livability of the vehicle. A car that's noisy, even with the windows up, especially for long stints on the highway, can be nerve-wracking.

Here are some simple ways to soften the noise coming into your car's cabin.

Cabin noise has four main sources: powertrain, chassis and frame, wind/aero-drag, and tires. For these, there are do-it-yourself fixes you can do that will dampen at least some of the noise. The first just costs some money. The second takes little money, but a fair amount of time and some effort.

Tire Noise

Most new cars come with tires geared towards fuel efficiency, which generally means harder rubber for less road friction. This improves fuel economy by lowering drag, but increases road noise as the tire absorbs less of the vibration created by any less-than-even surface (which includes almost all roadways).

Another trend are slim profile tires, or tires with short sidewalls. These low-profile tires also absorb less of the road because they have less "give" (flex) from side-to-side and less air in them to cushion the ride.

For most cars, significant amounts of road noise can be dampened simply by moving to a different tire. A softer tire with taller sidewalls, if it can be installed, will change ride dynamics and sound considerably. This is the easiest of fixes and requires only a few minutes of research and the money to change out the tires. Talk to your tire expert about what options you might have.

Noise dampening for Wind and Powertrain

The other highest contributor to interior noise in your car is wind and powertrain. Your engine, transmission, etc. all makes noise and the wind sliding around your car on the highway also makes noise. Some vehicles dampen this with various insertions of foam, engine covers, and underbody sprays. On older vehicles, those covers and some of that foam can break, fail, or have disappeared over time as mechanics and hard use have taken their toll on them. On newer cars, these may not have been included at all in order to keep the price tag on the car low.

In either case, you can buy noise-absorbing pads for aftermarket installation. Several makers have them, but the most common are 3M Sound Deadning Pads for automotive. The are heat and fire-resistant, relatively inexpensive, and have a self-stick side that makes for easier installation. There may be similar offerings from competing brands on the shelf at your auto parts store, so shop around some for the best price. Just be sure they are heat resistant and flame retardant.

These pads usually come in rolls that are a few feet per. You'll need as many rolls as you need to cover what you expect to cover in your car. Start with one and see how it goes, then get more as needed. For about $30 and two or three hours' time, you can make many subcompact cars seem almost at the luxury level with the noise dampening you'll accomplish.

Start by getting the easy spots first. Cut patches to fit and stick in place. Begin with the firewall, especially around the edges where welds and rivets attach one sheet of metal to another. Under the flooring is another good space, which you can also do from underneath the car if you don't want to remove the carpeting. Using pieces as long as you can get them to place, cover the driver's and passenger's floor pans as completely as you can.

If you have the tools and know-how, you can remove door panels and cover key exterior spots (be sure not to interfere with door locks and window operation) as well - stick it to the outer door skin. If you can remove the headliner, pull it down and put sheets of deadening foam to the roof as well.

Adding sound absorption to key areas goes a long way towards quieting down your ride. It's relatively inexpensive and easy to do too!