# Noise abatement in '01 Hyundai Santa Fe



## DSHornet (Jan 11, 2009)

This was what I entered on another board but a friend suggested I spread it around as a good primer on the subject. It was first posted in May, '09.



*So, you want to decrease the noise in your car? Me, too.

I started my noise abatement project in my '01 Hyundai Santa Fe in March, 2009. The road noise from the tires, the standard BFGoodrich Long Trail T/A's, was more than just noticeable, and the engine noise was more obvious than I thought it should be in an otherwise very nice car. In fact, before the Santa I had a '96 Kia Sportage with BFGoodrich Touring T/A's that were much quieter (the exhaust noise from the glasspack was another issue, though), so I knew the noise could be improved on.

This narrative is intended to describe my experience with my car. I think it will serve as a general guide on how to proceed and what to expect with most vehicles.

*First, some background.

My research started in fall 2008 by looking on various message boards and seeing how people addressed the noise issue. Some went the cheapest route possible by using asphalt-based material made for roofing applications and using home carpet padding to muffle noise. The roofing material had a problem with adhesion and smell. The carpet padding, if used inside a door or another unsealed place where it could get wet, would hold water and cause rust and mold growth problems. I decided to reject the asphalt-based products and be very careful how I used any carpet padding. A very valuable source of information is the web site http://www.sounddeadenershowdown.com/ which shows the quality issues in the various products available.

There are many vendors who sell noise deadening material, some more expensive than others, some better quality than others. As usual, the rules, "Caveat emptor," "You get what you pay for," and "There's a difference between cheap and inexpensive" apply. There are ways to get a good product without breaking the bank. It all depends on what you want to do and how much you want to spend. For the best quality and greatest variety of products to quieten a vehicle, the best vendor is probably Second Skin, but they are far from the least expensive. Many consider the best compromise between cost and performance to be RAAMaudio, which is where I bought the deadener and sound absorbent mat I used, but they are the only two products RAAM has available. There are several other vendors out there, but most sell the asphalt based products that make a car smell like a freshly paved road for months and may come unstuck after the weather turns hot in the summer. The idea of having my carefully applied deadener peel off the inside of a door and rub against window glass, and fail to deaden the noise I object to, doesn't appeal to me.

The butyl rubber based deadeners sold by RAAM, Second Skin, and others are more expensive but generally much better quality. They deaden noise better and tend to stay in place after installation on a clean surface, and any bad odors are gone after a day or two.

*Back to my car.

I started by ordering some RAAMmat BXT, Ensolite foam, and spray adhesive from Rick McCallum at RAAMaudio (RAAMaudio). I had some scrap carpet padding that I saw no reason not to use, so it was part of the job, too. The first part of my project was a little experimentation on the lift gate and rear doors, mainly because the area I was to work in was small and easy to get to. I started by using denatured alcohol on a rag to clean the inside of the outer skin on the gate and doors so the mat would stick as well as possible. (Some use lacquer thinner or other solvents that won't attack the painted surface.) Using a utility knife, I cut some pieces of mat and stuck them on the inside of the gate to the larger sections of unsupported steel that would tend to vibrate in resonance with road noise. There is so much cross bracing on the inner side that it was hard to use pieces larger than about eight inches long, so I had to cut the mat into smaller pieces to get them through the holes. (A word of caution here: There are many sharp metal edges that will cut a hand and arm, so be careful. Just expect a few nicks and cuts as you work.) After I put as much mat on the inner surface of the outer skin as I could, I glued a large piece of Ensolite, cut with scissors, to the inside of the lift gate trim using the supplied spray adhesive. I next glued a large piece of carpet padding on the Ensolite. The total thickness of the Ensolite and the carpet padding was almost too much to let the trim lay flat when I put it back, but the trim reinstallation went okay.

Next I took the trim off the rear doors and repeated what I did on the lift gate. I didn't cover the entire outer skin but I should have been more thorough, because a few weeks later I took the trim back off the doors and added more mat on the steel outer panels and the horizontal braces, and also glued Ensolite on top of that for additional deadening. If I had been more thorough with the rear doors the first time, I wouldn't have had to do it again. The additional deadening helped noticeably. I learned that adding deadening on the surfaces along the perimeter of the doors, to catch noise coming through the door frames, is a little detail that should be paid attention to. I had to remove a small section of carpet pad to let the control rods going to the inside door handle work easier.

Doing a really good installation job on the lift gate and the rear pair of doors can easily eat up a day for one person, probably less for two. The next step in my project involved much more effort over a week for me alone. I'm willing to face the fact that, even though my job maintaining a hospital keeps me in very good physical shape, I was born when Harry Truman was President. I could see this would be a challenge! Tylenol was my friend.

I started on a Friday afternoon by removing the interior trim and seats from the back and working forward. This sounds easy but is a lot of labor working alone, especially being careful not to damage plastic push pins, trim pieces, and fasteners. Putting hardware in plastic bags kept small parts from being lost. For those who don't know, car trim pieces look much smaller in the car than they do out of the car. The wife looked more skeptical as each car part appeared in the dining room, but she is a patient soul. She learned long ago to allow me my occasional wild hair. As trim, carpeting, and seats collected in the house, bare metal appeared in my trusty ride. After everything removable was removed, I used a vacuum cleaner to suck up all loose particles possible, and then went over all metal with the alcohol soaked rag.

Hyundai uses a pad under the carpet that is evidently meant to decrease noise, but I'm not sure how effective it is supposed to be with all the tire and road racket I had. The pad on the floor is loose and can be lifted right out, but there is a section of the pad in the lower firewall in the front foot wells that is held in place by the attachment points for such hardware as the pass-through for the steering shaft. I elected to leave this in place as I wasn't sure how much trouble it would be to reinstall it, but I lifted it at the lower edges as much as I could to apply the mat and Ensolite to the floor pan.

As I put down the deadener, I swear the car grew larger by the hour. Putting material every place I wanted involved a lot of cutting, sticking, and gluing. To make a very long story short, I got the floor pan finished and the front carpet and seats back in by Sunday night so it would be drivable. All the next week I spent afternoons completing the rear cargo area and the insides of the rear fenders, and putting the car back together. A digital camera helped remind me where things went. It's hard to take too many pictures. Since the front doors and rear fenders are where the stereo speakers are located, extra deadener went there. I had some half-inch Rubatex closed cell foam insulation that I used behind the speakers as additional deadener. I'm not sure how much it helped, but I'm sure it didn't hurt. I went a little overboard with the carpet padding under the carpet for the rear cargo area because it was a little too thick to let the carpet lay freely. I should have stopped with the RAAMmat and the Ensolite.

*Progress so far.

The entire floor pan is done with a layer of RAAMmat BXT and a layer of Ensolite foam. This includes the kick panels in the front foot wells, the trim on the B pillars, underneath the padding in the foot wells, a few places in and under the center console, and the rear wheel houses. The front doors have a layer of mat, a layer of foam, with a layer of Rubatex and another layer of foam directly behind the speakers. The door trim has a few pieces of mat on the larger areas of plastic, a layer of foam, and a layer of carpet padding. The rear doors are done with a layer of mat and a layer of foam on the inner side of the door skin, a layer of each on the perimeters, some pieces of mat, foam, and carpet padding on the door trim. The rear fenders, possibly the most complex area, are lined with RAAMmat, Ensolite foam, and Rubatex, with mat, foam, and carpet padding on the trim.

Future additions include mainly paying attention to the front foot wells and the inner firewall as far up as possible. The only way I can see to add material here is to carefully cut the existing pad, lay down the mat and foam underneath, then probably glue the pad back in place on top of the foam. This will involve partially removing or at least peeling back the front carpet and some trim removal. I also plan an eventual speaker upgrade, which will involve removing (again) the rear fender trim panels and the front door panels. At that time I'll add more material in places I didn't put it the first time around.

*Thoughts and observations, with 20-20 hindsight.

First, and most important, do your homework. When planning something like this, it's hard to be too prepared. Ask questions on message boards, visit vendors' web sites, and look at your own vehicle to see what will be involved once you start. Taking care to avoid mistakes is worth the trouble.

Doing a complete noise abatement project in a modern car involves a lot of forethought, expense, time, and labor. I think it approaches an engine rebuild in attention involved if a good quality job is desired. Allow at least a week for the job, a little less with a helper. Don't be shocked if the money spent exceeds US $400 for everything you want to use in the project. I worked in my carport; if you have a garage, you will be limited less by weather and losing daylight in the evening. Also, the neighbors will be less inclined to make cute comments.

Wear clothing that you can afford to damage. The butyl rubber of the RAAMmat, even though it's less messy than some other materials, will squeeze out from under its aluminum backing when you kneel on it and imbed itself in the knees of your jeans. It can also get on your shirt sleeves. The use of a "disposable creeper," sometimes known as an opened cardboard box, will help this, and you can always use it again when changing oil.

As mentioned before, be prepared for nicks and cuts from sharp metal edges. Using gloves that can be thrown away are a good idea here. I've seen a box of light cotton gloves for sale, just can't remember where.

The rubber of the mat is sticky, and the spray glue used to stick the foam in place is, too. This can be a messy job if you aren't careful, less messy if you are. This is another reason to use disposable gloves. I could get my hands clean with Goop hand cleaner, but it took a lot of rubbing.

Have a few extra blades for your knife handy for cutting the mat. Also, have a good, sturdy pair of steel scissors to cut the foam. The cheap ones with the plastic handles can break in the middle of your work. A tape measure and a metal straight edge will make trimming easier, and a fine tip felt marker will help forming material to fit in an irregularly shaped space.

When you spray the glue on the foam, the over spray will stay where it is. Spraying on old newspapers will help keep the work place neat. If you are outside, wind makes things harder.

Stay sober. If you think that a six-pack of Bud Light will make the job easier, think again. Let the brew wait until you are finished for the night. It's too easy to injure yourself, or do something that's hard to undo, if you aren't paying attention. Likewise, don't work until you drop. Quit for the night, then resume the next day.

This is a work in progress since I can think of more places to put the noise damping material: Firewall, inside the front fenders, the hood, probably a few other places.

So, that's my experience.


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## DSHornet (Jan 11, 2009)

This is a second installment in the noise abatement project in my '01 Santa Fe. This was first posted in November, '09.

My online buddy put me on to the idea of adding sound deadening in the front fenders. Actually, I thought about it but I didn't know how effective it would be, and I wasn't sure about taking the fender liners off the car. I've heard stories about the brittle plastic parts breaking on reinstallation. It turned out to be a non-issue. The job was easier than I thought it would be, and the return on effort was well worth it. With breaks to stretch the old codger's back and legs, it took about three hours on a beautiful Sunday afternoon. Here's how mine went.

I started by jacking up the car and removing the front wheels to make access easier. It was also a good time to do a quick visual on the brake pads and rotors. I had to remove the splash guards I installed a few months ago, and also took off the front fender cladding at the time. Removing the fender liners is easy - all you need is a #2 Phillips screwdriver and some patience when dealing with the plastic retainers. A little careful maneuvering brought the liners free.

On the right side, I applied RAAMmat to the insides of the body near the door hinges and also on the plastic liners from the 9:00 position to the 12:00 position. I applied two layers of sound absorbent foam to the mat on the body and then started to put the fender liner back in place. It was then I noticed something that my bud mentioned in a message: There is precious little space, a half inch or less, between the metal body at the leading edge of the door frame and the plastic fender liner at about the 10:00 position close to one of the mounting screws. I finally got the liner back in place and attached, but it took a little creative moving of parts.

On the left side, I applied RAAMmat to the body and the fender liner at about the same points, only on that side it would be from the 12:00 to the 3:00 position. I was a little more conservative with the absorbent foam, but I also used a little Rubatex I had left over from my previous noise abatement additions to the front doors and the rear fenders. As careful as I was in the tight location, I had to cut away a small part of the Rubatex to get the liner back in place. Also, I noticed in the front of the left fender there is a section of the air intake tubing for the engine that passes through the cavity just behind the left fog light. Since this may be, in effect, a resonant cavity for noise from the intake, I put some RAAMmat inside the fender liner and wrapped some asphalt impregnated cork tape around the flexible tube. Maybe it didn't help much, but it couldn't hurt.

Twenty-twenty hindsight suggests I could have put some RAAMmat and absorbent foam on the box sections at the top of the body inside the upper parts of the fenders, but I'm not sure if it would have improved the result. Putting mat and foam on the entire fender liners might help some, too, but again, I'm not sure if it would have been worth the small extra effort and expense in material. Lining the fenders? Maybe, maybe not. If I ever need to remove the fender liners again for any reason, I'll probably do it then. 

However, the result was WELL worth the effort! Engine noise is noticeably lower, and so is road noise! Thanks, Andrew! You da MAN! :laugh:


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## freemind (Sep 11, 2008)

Thanks for the write-up. One helpful bit that I can give you is, WD-40 will remove RAAMat from anything quickly.


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## DSHornet (Jan 11, 2009)

Freemind, thanks for the word on WD-40.

The weather was nice today before expected rain tomorrow, so I used the opportunity to play with the engine noise issue. I still had some intake noise on acceleration to address.

I removed the fender liner on the left side and took another look at what I needed to work with. Today's inspection showed that the box section of the body inside the front fender at the top runs from the leading edge of the body, directly behind the left headlight, all the way to the driver's door frame. What's interesting is the fact that the engine intake is routed to open inside the fender at the leading edge of this box section, effectively making it a kind of waveguide that transmits noise from the intake toward the driver. The end of the intake tubing can be seen next to the battery where it takes a right angle to go into the fender. The box section is not closed. There are holes outboard of the intake opening going into the fender at a point behind the left park light/turn signal, and also about halfway back directly over the front wheel. At the hole over the wheel, the box section is closed by a kind of bulkhead, but the waveguide effect still exists to direct intake noise into the fender (where it can resonate) and toward the driver (ditto).

I glued some Ensolite foam directly to some RAAMmat so it would be easier to install both in the very cramped cavities where I would be working. When I peeled the backing off the mat, I didn't have to worry about spraying adhesive in the small space. It saved time, material, aggravation, and mess.

I stuck a double layer of mat/foam on the inside of the fender behind the park/turn signal directly across from the opening at the front of the box section. I also stuck a layer of mat/foam on the inside of the fender across from the hole over the wheel. These were to catch noise that would strike the inside of the fender and resonate there. I then removed the battery so I could remove the black plastic intake tube (a 10 mm deep socket takes the retaining nut off) where it takes the right angle into the fender and the box section. I stuck some small pieces (about 1" X 4") of mat/foam on the inside of the right angle piece and also inside the box section opening. I didn't close the opening with the mat/foam, just put it around the hole. I went back to the opening in the box section over the wheel and stuck some more small pieces of mat/foam inside the box section at that point. The problem when working at this point is access because there is a large, stiff wiring bundle that is attached to the box section and runs across the opening that I was trying to work through.

The result of all this work is, as nearly as I can determine, no intake noise at all when cruising at a steady highway speed. The resonant note at around 3000-3200 RPM on the highway is all but completely gone, but that's at a steady 80 MPH. There is still some noise on acceleration (it will be pretty tough to eliminate all of it), but it's much lower and harder to detect. The most objectionable engine noise I can still hear is the mechanical whir from the engine itself, and I don't know what to do about that, unless I can go back into the interior at a later date and do some more mat/foam insulation behind the dash and under the front carpet. At any rate, gluing the Ensolite sound absorbent foam to the RAAMmat and installing both as a unit is a major improvement over putting the Ensolite over the mat in a two part process.

And that's the latest, folks.


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## 62Lincoln (Aug 27, 2009)

Very thorough write ups, thanks for the effort! Next time you're in the fender, it would be very helpful if you could snap some pics and post them...IF you're ever in the fender again!


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