Hello I recently acquired a 2010 Fit Sport and am in the process of doing some sound deadening work in hopes of make the car a bit more enjoyable for long highway drives. I did lots of research prior to purchasing CLD tiles and a generic sound blocking foam rubber layer, but still have a few questions.

I have my interior completely removed and have begun installing sound deadener. I have no idea how others cover every surface, as the product I purchased does not seem flexible enough. After doing additional reading I have concluded that 100% coverage doesn't improve the situation all that much, so I'm proceeding with 50-70% coverage (all flat areas) and not worrying about the curves.

More importantly, I'm wondering how to best deal with the (very limited) factory sound deadener in the front and rear floorboards, under the front seats, and small patches on the rear wheel wells.

It seems like my options are:
1) leave the factory deadener alone and install CLD around them
2) cover the factory deadener as if it was bare metal
3) remove the factory deadener and install CLD on the resulting bare metal

I will note that the factory sound deadener does not seem very effective, at least based on the noise/reverberation that results from tapping on bare metal vs the factory sound deadener vs the CLD I have installed. This is especially noticeable under the front seats and in the rear floorboards I have also noticed that some of the factory sound deadener (especially on the rear wheel wells) is partially separated from the metal and could be easily removed.

Any advice?

 

In my experience, using tiles instead of complete coverage results in deadening the panel from vibrating (which can cause noise), but does very little in sound insulation. In other words, tiles work well if you want to stop a panel from rattling due to bass from a stereo or from creating a resonance when going over rough roads, but will do little/nothing to stop road noise. Only complete coverage is truly effective against road noise unless your panels are vibrating/rattling when going over regular roads.

As for your question about the factory insulation, leave it in place and cover over it. The heavier the panel, the better. I would not remove one product to install another. I would use both.

 

No idea but a few thoughts.

The car audio fourms should have the best DIY advice.

You could buy or build a cargo tray for the hatch area. We have a different hatchback and that carpet & "cardboard" gizmo makes things much quieter. On that car it has a fairly tight fit but is not perfectly "sealed".

Check any rubber gaskets at the doors for proper fit and damage.

Remove any roofrack you are using.

Check that windows close and seal perfectly.

You might look at adding insulation to doors (study how the windows channel water to the bottom of the doors beforehand).

Look at adding sound deadening under the hood if it is not already there.

My buddy purchased hard rubber floormats and the car is much louder inside. So maybe thicker carpet floor mats and/or more soft insulation under the rug might help.

I have seen people remove the headliner and apply sound deadening to the roof.

New high quality tires might be quieter and some are designed to be quieter than others. Balance and rotate them frequently. Check air pressure frequently. Get an alignment from time to time.

Have an independent shop check exhaust for leaks. Flexpipes are always suspect.

 

Thanks GAFIT.

I wanted to add some additional information.

I might not have been clear in my initial e-mail, but I plan on doing 100% coverage (or as close as possible) with my foam rubber layer but was having difficulty getting high coverage with the stiffer CLD tiles. One additional question regarding the foam rubber layer: Do folks worry about covering the various weight-saving/ventilation holes?

My current CLD coverage is probably 75-80% on the outer door skins and rear hatch (+ a small amount in areas of high resonance on the inner layer of door/hatch where the interior trim attaches) and 75-ish% coverage of the spare tire area, rear hatch floor, and rear wheel wells. I have lesser coverage of the passenger floor area (maybe 40-50% at this time) because I have so far avoided the factory sound deadening material. I have not touched the roof as I am hesitant to mess with the side airbags/trim to remove the ceiling liner. However, I have plenty of CLD remaining so could revisit this in the future. I have also not attempted to access the inner firewall yet, although I will note that this area does not seem very resonant in my testing (obviously different from road/engine noise intrusion).

Regarding the factory sound deadener, on closer inspection the material on the rear wheel wells had large "bubbles" where it was separated from underlying metal. Perhaps not surprising in a vehicle built in late 2009. Tapping revealed the factory material was doing little to deaden or block sound, so I removed it (very easily) and replaced with CLD tiles, which improved the situation.

In the passenger floor area, the factory sound deadener is still stuck to the floor. I will look at covering it with CLD tiles today.

Then I'm on to my foam rubber layer where, as I mentioned above, I will try to maximize coverage.

 

Drew21
Have you continued with your quest to make the Fit more quiet? I am about to embark on making my Fit more touring (highway) friendly. I am getting too old for this s#$@ (neck and back issues) so I plan to have a sound shop do the job. I will let you know what they recommend and I will add as many pics as they will let me take. But nothing will happen until the end of April as that is the soonest they can schedule me.
DaveD (imn2it)

 

Hi imn2it. Sorry that I never gave an update on this.

I did spend a significant amount of time working to quiet my Fit. How much time? Well, I'm not entirely sure because I worked a bit each day over several weeks. I was out of work because of the pandemic and went home to help my parents around their small farm. It was probably more time than I should have spent, but it gave me something to do and it's always fun to work on a car. About halfway through the process my dad came up behind me and sardonically said "Have you ever thought of wearing earplugs?"

I will say that I previously watched Youtube videos and read on the internet where different people claimed to do this process on their own car in a few evenings or over a weekend, which I do not believe. I'm pretty handy, but I think that doing this well requires a significant time investment as well as lots of bending, kneeling, and stretching so it is not exactly easy work. If none of that sounds good to you it might be worth paying someone to do the work.

1) I completely stripped the interior from the car, except for the dash, A-pillar trim, and the headliner. As a side note, this provides a great opportunity to really clean all the interior panels, and I spent an entire rainy afternoon doing just that.

2) I used two Siless products. The first layer (patchwork placement) was 80 mil butyl sound deadener and the second layer (complete coverage) was 157 mil sound deadening closed cell foam. I used 50-55 sq feet of the 80 mil product and about 105 sq feet of the closed cell foam. I don't know if these products or better or worse than the more popular products, but the price was right for me and I couldn't see much different when comparing to the more expensive products.

3) The 80 mil Siless product was a bit of a pain to use, especially in tighter areas like inside the doors or up (as I high as I could reach) in the front floorboards and behind the dash. Initially I planned to completely cover the floorboard, but that proved difficult as the foil doesn't allow much stretching around curves. I found it far easier easier to cover an area with a patchwork of smaller pieces, and I have seen many people say that is all that is needed. As I was placing the product I did a lot of tapping with my fingers and a rubber mallet to note how the resonance of panels was reduced. Note that this product absolutely requires some sort of roller during application. I bought a set with several sizes of rollers, and also used the roller handles quite a bit to stick the butyl down into tighter areas.

4) The 157 mil Siless product is easier to work with, but is not without its own frustrations. First, it is super-sticky, which is great... if you get it where you want it on the first try, which is not always easy inside the doors. This product does have a bit of stretch to it, but once you go too far it rips quite easily. You also have to be careful as it's quite easy to tear it with your fingers or hand while trying to stick it down. I would typically place a piece where I wanted it and then use a microfiber towel to help distribute force as I applied some pressure (especially in tight areas like inside the doors). Also note that the closed cell foam is pretty fragile, so you can't be throwing your tools around inside the half-finished car or even stepping onto the foam while trying to reach a different area, as this will definitely tear the product. Attempting to get complete coverage inside the door panels or even across curved/convoluted areas of the interior requires lots of measuring before each cut, and it gets pretty tedious. In the end, I completely covered the interior of the doors and rear hatch, the floorboard and rear hatch floor, and up the sides of the inner body panels to window height.

5) I will note that for both of the above products I was careful to leave access to all holes (seat mount points, trim clip points, etc) and body plugs. This means that while I was measuring I would cut out a small hole from the material to allow access, before I stuck the product down. I also pulled up interior wiring and the tubing to the rear windshield washer and installed sound deadening underneath rather than covering it. My thought process was that I didn't want to have to tear up a bunch of these super sticky materials some day if I needed to make a repair. This definitely slows you down, but will be worth it if a later repair is required, as all I have to do is pull up the carpet and everything is accessible.

5) Once I had everything in place, it was time to reinstall the interior. Some of the trim panels were tight, but it went well until I was installing the trim around the rear hatch opening. I couldn't get the piece across the floor to fit, but after cutting away a slightly larger area of the 157 mil closed cell foam around the trim retaining clip holes everything snapped into place. I jokingly told my wife that I was afraid that the interior trim plastics would shatter after we hit the first pothole, but haven't noticed any problems so far. The interior trim would not have gone back in with any additional sound deadening products, so that is something to be aware of if you are having some installed.

6) I made one further modification, after reading about it on FitFreak. While underneath the car I noticed that underbody grommets for the shipping tie-down points were missing. These are supposed to be installed by the dealer prior to sale, but often weren't. I figured it couldn't hurt, so I ordered them from my closest Honda dealer ($23 for 4) and installed them. Because I did this at the same time I can't really tease apart the effect of the interior work vs the grommets, but at worst they would have no effect and I suspect they will block a bit of noise based on other forum posts.

7) So, did all this work reduce interior noise levels. I can absolutely say that it did, but I can't really quantify the difference for you. First you have to know that my previous car was a 2007 Toyota Yaris hatchback, which is a pretty loud car. Loud enough that I would have a headache after driving a few hours to my sister's house, and loud enough that my wife and I would have trouble talking or listening to the radio in the car because of the noise level (note: I have sensitive ears). All I can say is that after leaving my parent's houe with the Fit I drove for 15 hours and over 800 miles to get home, both of which are one-day records for me and feats I would never even consider in the Yaris. At the end of the day, I was tired, but I didn't have a headache and I had been able to listen to the radio at a low, comfortable volume during the drive. The second confirmation came when my wife went for a ride in the car and said "Holy cow, this is way quieter than the Yaris!" So, it's better and that is good enough for me.

I will say that I now notice the wind noise and engine noise more, and any little creak/squeak from the car (I have a squeak in my dash when it's cold), but the overall experience of driving the Fit is now pretty nice. Regarding the engine noise, once it warms up in the spring I may remove the cowl to see how accessible the engine side of the firewall is to determine if a heat-appropriate product could be placed there to block more noise, but it's not really a priority.

I have tons of pictures but don't know how to add them, but you probably already know what the inside of a car looks like and it's not too difficult to imagine what it looks like after adding sound deadening material.

Good luck.

 

WOW! That was one in depth and detailed reply. Way more than I could have hoped for. Thank you so much. I appreciate you taking the time to share your experience with me.

Sorry to hear that you have been out of work because of COVID. I too have been out of work due to the pandemic, but also my neck issues were making it difficult to do my job anyway. Luckily for me I was planning on retiring in the next year or two anyway, so retirement just started a bit early. God willing, this virus will lose its sting soon and we can all move forward.

As I said before I plan to have the local stereo shop do the work installing the sound deadening. This probably won't happen until May as I am currently working on some suspension and drive train stuff. I also plan on removing the back seats. I can count on one hand the number of times I've actually had passengers back there. Then I'll have the shop fabricate a flat surface "trunk" lid which will cover the spare tire well and the space formerly occupied by the rear seating area. This should also help insulate some of the noise in the rear of the Fit plus make a flat, easily accessible rear cargo area.

The biggest question I had, you mostly answered. Does all this sound deadening stuff work? Does it make the car quieter? Your seat of your pants feel seemed the answer is yes. My brother-in-law has a dB meter so I will try to come back and post some empirical numbers both before and after the work.

Thanks again for the in depth reply.
DaveD

 

I thought of a few more things that might be of use.
1) In the (2nd Gen) Fit, I think the most effective areas of treatment for reducing vibration and sound are the doors and rear hatch, the hump beneath the rear seats, and perhaps the rear inner fender areas. The area beneath the rear seat has a big section of metal that is only one layer thick - you can actually see the clips that hold down the interior wiring from underneath the car. The doors and hatch are of course a big area for noise intrusion. I used both products I described before on the inside of the door skins, attempting to cover everything I could reach. I have seen videos, especially from audio-focused sound deadening installs, where they close off the access holes on the inner door panel using sheet metal or other substances, but I didn't want to do that as I still want easy access if I need to fix a door lock or window regulator. So, I installed pieces of the 80 mil sound deadener product on flat areas of the inner door surface (behind the door panel you see from the interior of the car) and then I covered the moisture barrier material with a layer of the 157 mil closed cell foam product. My thought was that when the inner door panel was snapped back into place this would at least partially "seal" the access holes to sound, but still allow easy access through the removal of the moisture barrier material. The rear inner fenders do have some resonance so I treated them pretty heavily. On my car, the small sections of factory-installed sound deadener on the inner fenders were bubbled and peeling, so I removed that before installing the Siless products.

2) I put down both products in the floor of the passenger area, but I'm not sure how necessary it was. The floor is pretty stiff and large areas of the front and rear floorboards and the hump under the front seats are already covered with a thick asphalt-like layer of sound deadener material. I covered the existing sound deadener with my new stuff.

3) The rear hatch area, including the inner fenders and sidewalls, was quite time consuming to deal with because of all the curves, and I'm not sure how necessary it was. If you're planning on installing some sort of platform in the rear it might be easier to cover the underside of that with sound deadening materials and call it good.

4) The last thing I would suggest is that you make your goals clear when you ask someone to do the install for you. If you watch audio-specific install videos on Youtube, they do all sorts of crazy stuff to block all exterior vibration so that their fancy stereos sound as loud as possible. With that comes lots of weight (especially when the use mass load vinyl which is very heavy) and complicates re-installing the interior panels and trim. In contrast, I would estimate that my entire install added around 25 lbs to the car. If you're looking to make the car a bit more comfortable and quiet, you probably don't need that amount of cost, weight, and effort.

5) Regarding the back seats, they do come out very easily. If you want a flat cargo area, have you tried laying them down? I don't think you will gain much extra cargo space (vs laying the seats flat) if you build a platform level with the rear hatch deck, although I suppose you may be able to set it up in a way that allows you to access the area under the platform.

Good luck.

 

Some of the posts on this forum suggest that the front end is where sound deadening gives you the most bang for your buck. Specifically the strut towers (which are in the cockpit under the windshield), around the firewall under the cowl and the A-pillars. I take it you have not attacked those areas yet.

One reason that we Do-It-Yourself-ers do it ourselves is we can do exactly what we want, as well or poorly as we can live with.

But I have no choice but to explain as best I can what I am trying to achieve and let the installers do their jobs. That's a bit scary to me. Not only can it get very expensive, but also I may miss the results I am attempting to achieve.

I am also very concerned about adding more weight as weight is the enemy of the fun factor in cars. You can go fast in a Mercedes but there isn't a lick of fun in going fast (street fast, not track fast) in a 4600 lb car. There's always a price to be paid, I just have to balance less noise with more weight. I am hoping that removing the rear seats gives me a few pounds to work with. Not only that but I don't want to mess with front / read weight distribution much. A well made chassis is designed to carry its loads in certain ways and I don't want to screw with that.

Here's a pic of what I'm going for with the "trunk lid". Either


Fit Trunk Lid - GK Fit not GE like mine.

Or build a platform on top of the rear shock towers. Both of these have the advantage of a flat cargo bay. Maybe spray it with butyl and cover with carpet??? Plus in an emergency - a bed. Don't sleep well on the rear seat to spare tire well hump.

Thanks again for your informed recommendations. And barring unforeseen circumstances I plan on posting my results in a few months.
DaveD

 

When I first got my 10 Fit new, I had it rustproof. Partly to forestall possible rust, but also to help quiet it down. I can't say how much it helped, but it's pretty easy to do yourself. I also made a cargo area cover, partly to hide stuff from prying eyes but partly to contain any sound generated in that area.