I thought I would share as I go through the process of making my Fit quieter, or perhaps more accurately, less noisy!

What we're starting with here is a bog-standard 2012 Fit Sport, Automatic, GE, 25K miles. We love the car: I wanted something fun to drive, acceptable cargo room, and which wouldn't depreciate very quickly (read: cheap). That's because we take the train to work every day and the car just sits. It's a great car.

But highway trips of any real length have been a drag. So I trade cars for mom's new Outback, which is an overland luxury yacht by comparison. Part of it's the noise, and I'm going to do something about that.

Here's the thing: I'm not willing to tear the car apart. I'm well aware that this is the right way to do it. I learned a ton there. Butyl "dynamat", then thin foam, then MLV. But I've got a toddler, this is the only car, and so taking up the carpet to get at the floor is not happening. I've also taken out dash panels before, and I'm not going there either. Maybe you can see this not my first rodeo. But I've never taken apart a car specifically to make it more quiet.

So my big challenge is to achieve a more comfortable interior without getting at the floor. Other trim panels, as you'll see, are fair game.

Here's step one (these steps are in my order, not any kind of recommendation):

These are , soft with foil on one side. Not wanting them to slip, in this application I took off the foil. You can't see it, but this one goes as far up the firewall as you can get it.

This one addition made a noticeable change in engine noise: You can still hear plenty of it, but there's an unpleasant "edge" of high-frequency noise when it revs that is gone now. There's more of this stuff under all the mats, and the color and texture blend in really well. It's easy to work with, but pro tip, use tin snips not scissors. This one is cut short so that the mat retainers still work.

 

Next step was experimenting with butyl-backed ... stuff. No one really knows what this stuff is; Dad refers to it as "the lead stuff, except you can't buy that any more". You're right about that, Dad. What I bought on Amazon is Noico brand, it's made in Russia, it probably doesn't contain lead but it's probably not going to make you healthy if you eat it. Also, wear gloves: People say it's super sharp and it totally is.

From what I can tell, buying tar-based roofing substrate instead is a bad idea.



That's half way through my doing the wheel well and the driver side. You can maybe see the tiny amount of factory sound deadening over the wheel well. It may be carefully calculated to strike a balance between "this is undriveable!" and "I'm considering the Accord."

To my surprise this effort made very little difference. I could notice it, but it was minor. I didn't have any sound deadening material to put over this at the time, so I'm going to come back to it. There's a lot of noise from the rear over big bumps, and I don't think you have to just accept it.

It was at this point that I learned that taking apart the Fit interior is really easy. Just about every trim panel is held on by round clips, which come apart with enough gentle pressure. I'm not going to say you can't break something, but you don't need to be afraid to tug. That's why I started on the trunk: if I'm going to break some part of a trim panel, I'd like it to be where I won't see it. But it's fine.

 

It seems you're making decent progress, and it may be rather valuable when you're done for others to know what exactly gave the most quieting for the least amount of work.

If you have the original factory tires, getting some replacements that are quieter riding will make a noticeable difference as well. A reasonable portion—but certainly not all—of the noise in the Fit is tire noise that makes its way into the cabin.

 

That's a great point DrewE! At the end of the winter I did in fact buy new Michelin Premier A/S for the car - not because of sound but because the stock A/S got a nail and were close enough to replacement I just did it. I'm sure they're a little better than stock, but if you check out the ratings, they're not actually THAT good from a noise perspective -- I probably could have chosen better from that angle.

https://www.tirerack.com/tires/tires...oModClar=Sport

 

I insulate by using a philosophical approach.
That is, I believe when you have bought a sub-compact vehicle, that's functional and build priorities are NOT aimed at being cathedral like quiet. Road noise is inevitable.

I think tire change, is often overestimated as a saving aspect. All tires transfer noise, all tires wear. It's the surfaces you are driving on, much more than the tires. Not even the highest rated tire is going to make The Fit quiet.

Then you can do what you are doing. The process of attempted insulation. Adding insulation here..there..and looking for improvement.
And I suppose it can be created. But how much improvement is really possible? Is anyone ever going to sit in a Honda Fit and exclaim "This is one of the quietest automobiles I've ever been in"?

So, I look for white noise acceptance. It seems much easier to mentally block out the noise. Turn up the stereo, or open the sunroof. The world around us has an auditory decimal producing reality, and I can deal with the less than sound proof quality of driving a Honda Fit...as is.

That's NOT to say I'm not interested, or against anyone wanting to embark on these type of projects. Maybe someday I'll sit in the end result of one of these projects and say..."Wow, this is so much better".
But whenever I see threads, and the work and effort people put into trying to change the auditory reality of The Honda Fit...it never really seems worth it to me.

 

if you were like my wife who cares nothing about cars, then the fit in factory form is perfectly fine for its economical benefits and practicality.

 

Up in here is the base of the A-pillar. This goes back a surprisingly long way. Some people have speculated the pillars carry noise around, and run right by people's ears. Solution here: Some stiff foam stuff up in here. Think like a pool noodle, although in this case it was some packing material.

This makes, uh, no difference at all. LOL

 

Look right along the vertical edge of the door. I added extra silicon rubber weatherstripping material.

I had the idea that I was getting a large amount of noise right by my ear, which obviously is pretty close to the B-pillar.

Take a look at how the doors close sometime. Doing this I I learned two things: One, the car actually comes with two layers of weatherstripping. Two, neither are close to the exterior panel gap, which means there's plenty of opportunity for wind noise and dirt to get in. There's a big cavity over the B-pillar; if you tap the B-pillar it's totally hollow and ripe for transmitting noise. Also, try sticking your finger into the seal while on the highway - you can easily feel the window frame vibrating, which is not visible to the naked eye. (Fixing the latter is out of scope here, I'm afraid .. )

This one I prototyped (which I often do before buying things), with some bubble wrap sandwiched in the door when you close it. Depriving the Fit of that cavity open to the outside makes a big difference. I'm sure my Decible-O-Meter would show no difference at a steady cruise pre/post; I suspect we're talking about a small amount of noise at different frequencies right by one's ear, ie the kind of thing you still notice. Wind noise is down a little, and cars going by make less noise as well. I did all four doors, mostly because that's how much material I received.

Also, the doors now have a very intangible, satisfying "whumph" when they close. It's worth it just for this

You can potentially buy this stuff for a variety of door edges (top, front, bottom etc), and each one needs a different type of seal. You have to be REALLY careful not to put this on in a way that it's going to trap water, and that means making 100% sure you aren't blocking off the bottom-of-door drainage holes. I might come back to some of the other edges - the bottom one feels like it has a lot of potential - but for now I'm going on to other things.

Does anyone know how to pull off the driver's door interior panel? I've got the two screws off, but for the life of me I cannot pull any of the clips free. I'm not super strong, but other interior panels have come off just fine.

 

Okay, here's update on the back!

Step 1: Noico vibration dampener again. I was a bit better structured this side; practice makes, I guess, perfect. Or better anyway.




Step 2: Some of foam sound insulation. It's easy to work with, but I wish I had got something thinner - a little hard to put the trim pieces back in place. This is adhesive on one side, so it sticks.





I gotta be honest, after that work, I detect only a minimal reduction in noise. So for those looking for result-for-effort, to my surprise this one scores low. Now, maybe if I did the entire back at once I would feel differently. Keep in mind I'm doing pieces a little at a time. I think it's made a difference on gravelly surfaces, where pebbles are thrown up against the unprotected metal, so that's good. But that's a very small portion of driving.

Still can't figure out how to get the driver's door panel off I can't tug it hard enough to pull the clips out!!

 

Whoops, almost forgot this one - the center console! Gotta admit, I mostly did this to see how to work with the adhesive foam. But to my surprise, there's actually some noise from the transmission that is noticeably gone with even a minimal amount of padding. (Stock, there is none, which is appropriate given the transmission noise is not objectionable).

Can't really see where I put it, but thought the picture of the exposed transmission might be interesting.

 

The transmission on a FWD car is under the hood with the engine. The plastic bits with the shifter are just part of the shifter. I wouldn't expect any transmission vibration/noise to be transmitted through the shifter cable, so trans noise is surely coming through the floor or firewall structure.

With that said - I don't doubt that putting damping material under the console would block some of the transmission whine, of which there's plenty on my 2012 automatic Fit Sport as well.

I've thought about going down this same route, and you've done a good job of combining mass damping with acoustic foam. We'd road trip my Fit so much more if it was quiet, but as it stands, the NVH wears on the entire family very quickly. My wife drives a Lexus RX 350, so I'll always loose the "which vehicle should we take to Chicago?" debate... That Lexus drives like an old school Mercury Grand Marquis... sigh...

Be aware; some of this is structural. That is to say, the suspension & subframe design of the vehicle results in a significant amount of transmitted road and engine/trans vibration to the body. Unfortunately, you will struggle to silence that very effectively with DIY methods.

Not to discourage; keep up the efforts and keep posting your results! You're helping me hone in on where to focus on my future sound deadening project.

Dan

 

Thanks, and yep, I'm realistic about what can be added VS aspects that are fixed in the design phase. For example, what other car do you know with the top of the front strut towers under the windshield? Can't be very many! And a good reason for that: they transmit noise into the cabin. Things like that, or the gas tank not between the rear suspension and the people, are reasons the Fit is so spacious ... but they have definite design tradeoffs relating to noise and comfort.

 

Hilarious semi-update:

Wife's firm assigned her a client that's farther away, so while we figure out the logistics of day care, I'm temporarily borrowing an old Honda del Sol that my dad has hung on to. It's an extra car for him that's just kind of fun, so by taking it for more than a few days I'm not inconveniencing him. It used to be mine, until I went to sell it and he took first dibs on it! So for now, I'm driving the 3 year old to day care in the del Sol. She loves the car, immediately started referring to it as "her red car," and describes it as "loud!"

The Fit immediately has gotten at least 20% quieter

 

Very funny! Everything is subjective.

The Fit, while I love it, is insanely loud to me. I drive a Lincoln. Wife finds it loud, but bearable. She has commuted on the highway with it for 9 years. We went car shopping and discussed the cars after each drive. 3/4 of the cars I got out and said...too loud! Not comfy! She'd get out and say how quiet and comfy it was compared to her 9 year old Fit.

Everything's subjective!

I have owned quiet luxury cars and loud sports cars. I don't mind exhaust noise, but I'm not a fan of road noise. Once owned a Nissan Sentra Spec-V. Used Dynomat on EVERY inch of the interior. Even the firewall and roof. Was a sound system car. In the end, it took away a lot of the noise, but I was still disappointed. Discovered a large portion of the noise was coming through the thin, cheap glass.

My Lincoln has layered sound resistant glass. It's crazy quiet.

My point to all of this is that the Del Sol is the best mod to "quiet" your Fit. For the most part, cars are either built quiet or not. Trying to make one quiet that starts off really loud is near impossible.

 

You got it! Very subjective.

My father in law (actually his wife) has a Lincoln as well. It's fantastically quiet. A great car for passengers ... and because he's the only person in the US who bought a MKT for personal use instead of fleet, when we go to hotels people think he's a livery driver. This is endlessly amusing to me.

I notice the Lincoln, as well as the Chrysler 300 I rented for travel recently, has the metal window frames sealed off with plastic surrounds, plus there's a third seal in addition to the normal two. You won't be putting custom plastic surrounds around the window frame of a Fit! Or acoustic glass. That stuff has to be engineered in from the beginning ...

 

Some amazing feedback for y'all -- I cut road noise noticeably by stuffing some sound absorbing material under the rear seats, ie where the rear suspension is separated from the passenger compartment by only a sheet of metal.

I probably wouldn't have thought to touch that area, but my brother commented that while moving house, he transported a bunch of bedding in the rear seat and the car was quiet. He suggested that most seats have the gas tank between the road and, um, your bum ... but the Fit doesn't, so there's opportunity for vibrations to be transmitted inside.

And dang he's right. I followed up with a little more insulation directly over the torsion beam cavity, but it's the under-seat area that makes a difference. And it doesn't seem to matter too much what you stick there: I tested with some useful packing material that also absorbs sounds, and the center part is - yes - a towel.

I wasn't sure this would do much, but my dad got in the back of the Fit for a short drive - owning a Fit himself he usually sits in the much quieter front seat - and asked, "Did you do something? It seems quiet in here..."

 

Thanks for the update. I wonder if it would help to use some sound deadening material on the rear floor boards and up into the rear cargo area?

 

I'm not sure where you mean. If you lift up the seat bottoms there is a flat area under the seat, very close to the ground. Combined "carpet" and carpet padding-insulation, sheet metal, and then below that I think you are outside the car. But as you move toward the rear of the car there is an area that is higher off the ground, that angles up to meet the floor of the luggage compartment. There is carpet combined with carpet-padding-insulation here too, but it is several little pieces here, some of them clipped to sheet metal with plastic clips.

Should I just stuff a pillow under each seat and listen to what happens?

 

Well, I had my 2010 rustproofed when new, including extra thick undercoating. I also put down those custom form fitting mats. Finally, I made a cargo cover out of masonite. It all helps a LITTLE. Never gonna be a Rolls, though.