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Sound Deadening Model 3
- Thread starter fly2damoon
- Start date
XLR82XS
D M C
I'm wondering the same thing. I've sound deadened the entire rear of the car and addressed every possible rear rattle location that I can think of but still get a buzzy, rattle sound over rough or uneven roads.
I checked the rear wheel wells and there doesn't seem to be any play, made sure license plate screws are tightened, and taillights are secured (one had a squeak that I adjusted) but I'm running out of places to check. I had the aero shields replaced with a newer version and there were no sound differences between the two so I don't think there are any bolts that need torqueing under the car.
I've finally been afflicted with the infamous front upper control arm creak @ 15k miles but the sound from the rear doesn't sound the same.
If you find out anything, please update. I'm going to continue deadening for the next few days and searching for what's loose and knocking in the back. I'm waiting for some more MLV in the mail and I'm going to finish covering the wheel wells. I swapped the rear suspension recently making sure everything's torqued to spec and it still makes a bunch of rattling noises in the rear. It sounds like my car is falling apart when going over bumps.
An apparent rattle I found so far is the white charging board that leads to the charge port. It's a bit loose. I wedged some foam tape underneath and it's solid now.
The rear deck has a section where it feels like the adhesive failed. I think this is a source for rattling too. I'm going to eventually see if Tesla will replace the deck.
Did any of you put MLV on the wall next to the sub? I wonder if this will weaken bass response. I've applied some CDL on the walls so far.
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This is my biggest suspect. I partially removed the rear deck to check for loose connections but the adhesive is weak and causes a crunchy sound when I tap on it. I'm not sure if that could cause the noises I hear when driving but I've tightened up everything around it in the cabin: Felt taped C-pillars, foam around rear seat belt tensioners, felt taped ISO fix latches on rear deck, felt taped rear seat latches, had rear seat handles replaced because they rattled, taped down plastic pieces behind zippered carpeted seat back, replaced side bolster clips, filled rear deck cutout with foam, covered rear trunk roof with soundproof mat, checked both rear doors for loose connections and sound deadened... and yet the noises are still there.
I have a service appointment in a few days and i'll see if they do anything. I believe they put foam around the third brake light previously but that didn't fix anything so I'm not very optimistic.
XLR82XS
D M C
when i push the rear deck up from the trunk, there's definitely a rattle of some sort. i'm going to completely dismantle the deck this weekend to see if i can secure it. i also hear the third brake light housing can be a source of rattles but you need to remove the deck to reach that.
When I took it in a while back they insulated the 3rd brake light because I’m guessing it’s most often the source of noise but it did not resolve the issue for me.
I’ll see what they say/do for my appointment this week and may have to tackle the rear deck again. It’s just a pain and I’ve been putting it off.
Completed my sound deadening project for my car. I’ve been having rear rattling issues so I decided to tear the rear down and sound deaden along the way. Going in I knew the rear trunk and wheel wells were the loudest areas resonating sound.
Stripped rear trunk liners and seats. Notice how little oem sound deadener there is. Most of the sound deadening in the rear is from the bottom seat and liners. Tesla uses acoustic foam under the seat and liner.
Subwoofer out
Added Second Skins damplifier to dampen vibrations and resonating panels. When you knock on the trunk floor it sounds like a drum!
Added Second Skins Luxury Liner Pro and mass loaded vinyl for sound blocking on the wheel wells.
Complete. Mass loaded vinyl and decoupler in the trunk wall. Luxury Liner Pro on motor and floor of trunk.
I took a drive at various stages during the process since this took a few days to complete.
With the rear completely stripped to the metal, the car was LOUD. There was no dampening from the oem seats and liners. The sheet metal was the only barrier to the outside. You can hear the tire noise resonate all over the cabin. The motor was also crazy loud.
With the sound deadening damplifier sheets applied, the car was still very loud. Not much has changed in term of road noise. “Dynamatting” doesn’t do anything for road noise but helps with vibrations.
Went for a spin after applying mass loaded vinyl to the wheel wells and trunk. This made a difference. Road noise was noticeably reduced even with the car still stripped. I can compare it to how the car normally is with the seats folded down.
Went for a drive again with the liners and rear seat in. The car is considerably quieter. The tires used to resonate sound all over the cabin and sound droney on the freeway. Now that drone has been considerably muffled. The difference is very noticeable. I’m convinced most of the road noise is from the back and resonates up the shock towers and wheel wells into the cabin. I don’t plan to do the doors or anywhere else since the car is pretty quiet now. I also heard doing the doors, floors, and front wheel wells made little effect. The best bang for buck has to be the trunk and rear wells. I highly recommend properly deadening the rear if you want to quiet road noise down. Rattling is still there when I go over bumps and I’m pretty sure it’s the rear deck. Just going to bring it in and see what they say about the deck.
Stripped rear trunk liners and seats. Notice how little oem sound deadener there is. Most of the sound deadening in the rear is from the bottom seat and liners. Tesla uses acoustic foam under the seat and liner.
Subwoofer out
Added Second Skins damplifier to dampen vibrations and resonating panels. When you knock on the trunk floor it sounds like a drum!
Added Second Skins Luxury Liner Pro and mass loaded vinyl for sound blocking on the wheel wells.
Complete. Mass loaded vinyl and decoupler in the trunk wall. Luxury Liner Pro on motor and floor of trunk.
I took a drive at various stages during the process since this took a few days to complete.
With the rear completely stripped to the metal, the car was LOUD. There was no dampening from the oem seats and liners. The sheet metal was the only barrier to the outside. You can hear the tire noise resonate all over the cabin. The motor was also crazy loud.
With the sound deadening damplifier sheets applied, the car was still very loud. Not much has changed in term of road noise. “Dynamatting” doesn’t do anything for road noise but helps with vibrations.
Went for a spin after applying mass loaded vinyl to the wheel wells and trunk. This made a difference. Road noise was noticeably reduced even with the car still stripped. I can compare it to how the car normally is with the seats folded down.
Went for a drive again with the liners and rear seat in. The car is considerably quieter. The tires used to resonate sound all over the cabin and sound droney on the freeway. Now that drone has been considerably muffled. The difference is very noticeable. I’m convinced most of the road noise is from the back and resonates up the shock towers and wheel wells into the cabin. I don’t plan to do the doors or anywhere else since the car is pretty quiet now. I also heard doing the doors, floors, and front wheel wells made little effect. The best bang for buck has to be the trunk and rear wells. I highly recommend properly deadening the rear if you want to quiet road noise down. Rattling is still there when I go over bumps and I’m pretty sure it’s the rear deck. Just going to bring it in and see what they say about the deck.
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Hi @aspec818 - that was a great post, thanks! Would you mind sharing the list of materials for the last step that did the most improvements, with the mass loaded vinyl? I'll probably attempt it myself as the next project (haven't done much in regards to sound deadening).
Also if there's another post showing how to strip the rear part of the car that would be helpful as well. Maybe it's in this thread, which I read several months ago, it's been a while. Or I'll figure-out bit by bit myself.
Also if there's another post showing how to strip the rear part of the car that would be helpful as well. Maybe it's in this thread, which I read several months ago, it's been a while. Or I'll figure-out bit by bit myself.
Here's the material list for sound blocking.
Mass Loaded Vinyl in 1lb (per sqft variant). I used about 32 sqft of MLV.
Adhesive for the Mass Loaded Vinyl- either strong double sided tape or spray adhesive would work.
Foam Decoupler- recommended if you're going to run an aftermarket subwoofer in the trunk. The MLV by itself can rattle against your panels otherwise. At the very least, you can lay some under the MLV on the flat panels of the trunk. I used Luxury Liner Pro by Second Skins for the flat areas. Luxury Liner Pro is MLV that comes with the foam decoupler layered already, saving you a step.
HVAC tape- required to seal any open seams. Try to cover as much open seams as you can. Otherwise sound can pass through.
Butyl based sound deadener (dynamat, killmat, noico, etc)- great to quiet any vibrations. See my pics above where I placed them. I also applied some in the trunk lid and it now closes with a nice thump.
Optional:
Acoustic Foam- I stuffed cut up acoustic foam in the open crevice in the shock towers. Not sure how much this helps but anything to absorb as much sound waves as possible.
Tesa tape- stop wires from rattling against your panels. See if you have any wires that can potentially rattle when you're back there. You can wrap Tesa tape on the contact points.
I didn't see any actual tutorial in removing the panels in the trunk. I just pieced some videos together on youtube and did a few google searches. But it's not difficult at all. The panels are just held in by clips. In order to remove the trunk floor liner, you need to remove the back seats first (back rest and bench).
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i didn't touch the rear deck yet. I have a service appnt to see if tesla can pinpoint the rear deck rattle. if not, i'll need to remove and see what's going on there.
Thanks for the detailed write-up! I started this project as well. I only did the lower trunk and parts of the wheel well. I used the same materials-- damplifier pro / luxury liner pro. I noticed that once I put down the damplifier+luxury liner, the lower trunk panel didn't sit as far down as before. did you take off the stock foam that was underneath the trunk liner?
I have rear deck rattle as well and I also have seen the naked rear deck in person. The rear deck is held with glue gun type of adhesive, there are few local members have put dynamat to stop the rattle. The C pillars also need some fillings and it's not difficult to kill the noise.
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