Sound Deadening Material?

First, congratulations Chris on achieving 400,000+ with your Prius. That is quite an extraordinary feat! And thanks for your report. Now I know I'm not completely nuts, and just "imagining" the noise.

This is my first Prius. So I don't know if the prior generations are "rattle traps" as you mention. But I share your opinion, in that my new '16 Prius Three seems excessively loud inside. Compared to other cars I've owned in the past, I would say my Prius has the highest cabin noise of any. After purchasing, and driving it for only a week, my first thought was: Toyota lied. This new "Global Platform" is not quiet at all! But many veteran Prius owners disagree with me. Perhaps they are so accustomed to their noisy Gen2's and Gen3's, that the new 2016 really does seem quieter to them.

I'm pretty sure my Toyo tires are mainly to blame (but they have actually quieted down a bit since I've put on 1,400 miles.) But in general, the cabin is still pretty darn noisy. My guess, is that there is very little insulation. The engine "growl" is very clearly heard upon acceleration. And lots of road noise seems to come in from the doors and floor. Disappointing, for sure. However, I can live with it. I'm already getting used to the sounds, and just being thankful for all the other positive things about the car. I'm not mechanically skilled enough to start removing door panels, ripping up the floor, etc. But I sure would like to see what (if anything) is in there! Let us know if you find out.

 

Only noise I get is the vent sunroof not closing properly. Causing wind noise. Putting the sunroof in horizonal open and close then seals or should I say levels the back part of the moonroof to the metal roof skin eliminating wind noise. Opening the sunroof via vent position then closing it from vent position results in windnoise.



LG-H901 ?

 

by almost all accounts, gen 4 is quieter than all past gen's. comparing it to a car that has been sprayed and dynomatted makes no sense. even with 438,000 miles, the dynamat is still there.
gen 3 is reasonably quiet, not much better than gen 2, and tyres definitely make a difference. if gen 4 is quieter, all the better, but lexus? no, i don't think so.

 

agreed, i wasn't talking about rattles, just exterior noise. again, most owners who have had gen3, and some gen2 and 3, say that gen4 is much quieter.

 

I guess not. In for an answer but will most likely not do it. Wheel wells need something but I am afraid to block some hidden drainage pattern/design or cover up an important part.

 

If the Gen4 is much quieter than the Gen2 and Gen3? I'm sure glad I waited several years to get a Prius!

But the fact is, in my not-so-humble personal opinion, I challenge anyone to ride with me for a couple hours, and declare that my Gen4 is "quiet." On the freeway, the road noise / cabin noise will fry your nerves. Again, only my opinion, but it's impossible to have a relaxing drive at highway speeds. It's a combination of noisy tires, bad pavement, and lack of adequate sound insulation. That's just the way it is.

 

Yep, I tell my wife to get over it. Fresh nasty asphalt is very quiet.

 

I'd love to yank off the door panels, and have a look in there. But I have no idea how to do that and I'm afraid I would break something. I also considered spraying underseal in the wheel wells.

I did take out the spare tire yesterday, removed the foam, and applied some stick-on sound deadening material in the tire well and on all the metal surfaces. But I doubt if it will help much, if any. All the noise is up front, in the cabin.

 

Bisco, time for a drink yet?

Last night I had a glass of whining with a full lime. Good.

 

i hope you didn't really post that at 7:05 a.m. like it shows.

 

It's the tires, when we run our winter tires it's like a Lexus.

 

Noise? What noise. I'm deaf from all the noise. Pitty the ignorant nuts who are inflating their tires to 60 psi !

 

Door panel removal is pretty easy. There are three screws that you need to remove before just yanking off the panel. One is located behind the door handle. You need to pop off that plastic cover to expose it. There is one under the padded arm rest, and another under the trim with the window controls. The arm rest needs to come off first. Both of these are held on by plastic clips and come off easily with a good yank.

For the front doors, you'll also need to detach the light at the bottom (it's connected by a clip) and you'll need to take out the door handle from the panel. An alternative to taking out the handle from the panel is to just pop the metal wires from the ball sockets attached to the handle and locking mechanism.

After removing the screws, find some leverage on the bottom of the door panel (i found that the inner portion had a little something to grab) give it a good pull. You can't be afraid to break something, it takes a bit of force to pop the panel from the plastic clips holding the door trim in place. Work your way around the bottom and sides. The last step is to "lift" the door panel to dislodge it from the top. There are 10 in total for the front doors, i forgot how many for the back. I was able to retain all but 1 clip from removing the panels on all four doors and hatch. Thankfully this is an easy fix, as you can just order a replacement trim clip set amazon or something.

Tools that you might find helpful are a plastic trim panel remover to help get some leverage in places that are just too small for your fingers. A flathead screwdriver could technically do the job, but that might just result in scratches.

In regard to the wheel well, i found that a significant amount of noise came from there. The sound from back there definitely carries to the front of the cabin. In addition to the butyl stuff like dynamat, I also cut to fit a layer of decoupling foam and a sheet of mass loaded vinyl over the entire trunk floor (over the spare too). This didn't cut out the noise, but it noticeably muffled the road noise. Perhaps a better way to describe it is that it lowered the frequencies of the road noise, so it didn't sound so harsh over rough or bumpy roads.

Products like dynamat minimize noise from vibrations. Noise barriers like MLV (mass loaded vinyl) are used to help minimize outside noises and road noise. For MLV, there should be as close to 100% coverage as possible, and there should be a layer of decoupling foam between the MLV and the metal surface of the car for it to be effective. I've read that dynamat only needs ~50% coverage or something, but it was too late when I found out and did 100% anyway. I hope you find this helpful. Let me know if you have any other questions.

 

This may help you too with the door panel removal.

 

Did you do anything for the front wheel wells? I feel like a large amount of noise comes from that area and was debating on trying to take out the wheel well liner and apply CLD and/ or CCF+MLV.

Also, how effective would you say your trunk modification was, compared to the doors? The trunk application you describe seems to be low effort (relative to the doors) for a decent result.

Lastly, any opinion on whether/ not CCF+MLV beneath the front and rear floor mats, but above the interior carpeting, would make any difference?

 

Only an opinion ....
I suspect most of the noise is coming from behind the rear seat. My vehicle is much quieter with the luggage cover closed (or with luggage in the area) than with it open. If that is correct, it's an easy area to apply sound deadening.

Second, I blame the tires. My G3 was much quieter with Michelin Energy savers that the OEM tires.

Finally, it's the roads. Smooth asphalt is perfectly quiet. Concrete (especially when grooved like in the west) is noisy, and the pea-gravel embedded in a thick asphalt slurry is absolutely the worse. The highway department must love that surface because they are applying it over asphalt and concrete everywhere here in the west.