///// Sound deadening / sound proofing car /////

Andyinchville1

Veteran Member
Joined
Apr 7, 2016
Location
Virginia
TDI
2003 Jetta TDI wagon, 5 sp, 226K miles
Hi All,

I drive alot and want my car to be quieter.

I have read alot of threads and articles here and online on making the car quieter but wanted some opinions from those who have done this already.

I plan on doing the following :

1) I plan on removing my front wheel liners to clean out the dirt and check for / rust and POR 15 as needed .... I did this last year too.

I have read that spraying the wheel liners with rubberized undercoating or bed liner helps . I bought rubberized undercoating BUT I wonder if the bed liner idea is better?
Has anybody tried both ? which works better ?

I also bought a bunch of Kilmat off Amazon and have read that some people stick this to the liner as well.... I'm guessing the side inside the engine compartment?

I would prefer to spray the fender liner off the car to not worry about overspray BUT I assume I would have to keep the liner propped to approximate the shape of the liner in the wheel well otherwise will there be problems afterwards ? do most people spray while it is still in the car or off the car?

I have read that it may be a good idea to spray the actual metal of of the car while the liner is out ... I even read about putting a bolt behind the fenderliner at the bottom so the water drains out and the dirt can't fill in and cause rust .... is this something that really works?

2) Panel for panel - which areas give you the most sound reduction ? I would like to eventually have all areas done BUT I want to start with the areas that make the most difference.

In order of most sound reduced .... what is the best order to do it in ?

Any idea what percentage of sound reduction is associated with each section?

1) Front Wheel wells
2) Rear wheel wells
3) Driver side door
4) front Passenger door
5) left rear passenger door
6) right rear passenger door
7) front floors
8) rear floors
9) hood
10) headliner / roof area
11) behind the dash (upper area)

3) I bought enough Kilmat to do everything BUT was wondering if I should buy any other stuff (like closed cell foam , carpet padding , heck although it may look funky I thought about acoustic foam tiles like in music studios .... has anybody tried that?

Anything else to think about sound deadening wise?

Thanks in advance for any and all help

Andrew
 

STDOUBT

Veteran Member
Joined
Jul 30, 2007
Location
Portland, effing Oregon
TDI
ALHx2
I have read that spraying the wheel liners with rubberized undercoating or bed liner helps . I bought rubberized undercoating BUT I wonder if the bed liner idea is better?
Has anybody tried both ? which works better ?
100% bad idea. Water will get under it eventually. And it won't dry out. You know the rest. Even the 3 Lbs. of potting soil that collects behind the front wheel wells dries out - because it gets air to it. I live in a rainy place and drove my car for 11 years before I ever cleaned out the wells, and not a sign or speck of rust in there. The no-salt-roads really help. At any rate, don't use anything (at least on panels outside the cabin interior) that can trap water.
When I eventually re-do my headliner the inside ceiling is getting wall to wall 1 cm closed foam self-adhesive. Mainly to keep the cabin cool. Doors will get it too if I ever "have to" gut them.
 

tdihopeful

Well-known member
Joined
Oct 23, 2008
Location
California
TDI
03 2dr 5sp Golf
Hi there I'm sorry to not offer anything firsthand experience to youre thread but I thought it could be informative in a way that I was considering not for noise reduction but for insulation from cold temperatures. I had considered how hard would it be to fill all major panels with expanding foam. There are other considerations such as bridges from outside the outside of panels to inside of panels that would be unreasonably difficult to address but it seems filling panels with foam and insulation of the floor pan would with removable panels for windows would make for a much nicer ability to inhabit the car in very cold climates without necessarily having to run the engine or auxiliary heat constantly.
 

jettawreck

Top Post Dawg
Joined
Aug 2, 2004
Location
Northern Minnesota-55744
TDI
2001 Jetta and 2003 Jetta
Hi there I'm sorry to not offer anything firsthand experience to youre thread but I thought it could be informative in a way that I was considering not for noise reduction but for insulation from cold temperatures. I had considered how hard would it be to fill all major panels with expanding foam. There are other considerations such as bridges from outside the outside of panels to inside of panels that would be unreasonably difficult to address but it seems filling panels with foam and insulation of the floor pan would with removable panels for windows would make for a much nicer ability to inhabit the car in very cold climates without necessarily having to run the engine or auxiliary heat constantly.
I live where it can get -30*F. Driven my old work commute many times in those temps. Car sets in an unheated garage overnights, outside on the street while at work. While a bit slow to warm up, heated seats are a big plus, but with a good thermostat and full radiator covering (coroplast board) it makes good heat when kept busy on the highway. "Insulating" would probably block body drain holes/passages and cause many more issues than benefit. Sunroof and shade are along with the single pane window glass the biggest heat gain/loss areas (like any such vehicle).
Most of the time, re-engineering the design causes more problems than it solves.
 

ZippyNH

Veteran Member
Joined
Apr 22, 2015
Location
Southern NH
TDI
2015 JETTA TDI SE
Over the years there have been many posts on this...
My take ... don't spray extra stuff and in side or outside, you will catch dirt, block drains and cause huge rust issues.
What works, is to add adhesive backed sound deadening mass panels to bare metal areas inside the cabin, then multi layer (density and weight) foam as a backers to your carpet.....
It's all commercially available, often in kits.
Maybe do use a good rust fix,/prevention on the exterior based on your long-term plans to keep the car, a product that self-heals, like wool-wax is very effective at fixing itself when a rock chip nicks it...
For temps, the foam carnet backing will help.but a simple 100 watt tungsten lightbulb left on in your car will likely due more if it sits more than 8-12 hrs.... single pane glass is near worthless for insulin and the designer's of you car knew they had an near endless source of heat, the engine.....
Don't reinvent the wheel.....
 

tdihopeful

Well-known member
Joined
Oct 23, 2008
Location
California
TDI
03 2dr 5sp Golf
The ALH TDI at idle gets more than 50mpg equivalent perhaps it's best just to run the engine or maybe I invest in a Diesel burning heater that could be more quiet and share fuel with the car.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
Northern MD (HAGERBUSH)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
Try again. It's much more. 0.08 to 0.11 gallons per hour over 14 gallons? Yea, not even close. More like 5 to 8 days at idle. Or like 515 mpg. 24hoursx60mph over 5 days divided by 14 gallons.
Basically it's the equivalent of putting 2500 miles on the odometer.
The ALH TDI at idle gets more than 50mpg equivalent perhaps it's best just to run the engine or maybe I invest in a Diesel burning heater that could be more quiet and share fuel with the car.
 

Andyinchville1

Veteran Member
Joined
Apr 7, 2016
Location
Virginia
TDI
2003 Jetta TDI wagon, 5 sp, 226K miles
Hi All ,

Thanks for the replies and input...

Outwardly the car is not super loud interior wise ... until I ride in my dad's
Buick Lesabre.... then comparatively my car is very loud ....

Actually when driving and talking hands free using the speaker phone it is hard to converse ... mainly difficult for me to hear the phone even with the phone at high volume because the phone is stuck on the windshield mount fairly far from me (blue tooth earpiece is doable but volume has to be fairly high and I have to stick an earplug in my other ear to hear It better ...).

Ultimately convenience and fatigue resistance over the hours spent driving are my main reason for soundproofing the car.

I agree with the ideas about not making potential areas where water can collect ... i.e. undercoating where the undercoating may form pockets for moisture to collect and cause rust ... I imagine most undercoating failures are caused by inadequate surface preparation or faulty products but I really don't want to open a can of worms either so I'll probably hold off on spraying the undercoating directly behind the wheel wells on the actual metal but rather simply spray the undercoating on the plastic liner itself.... worse come to worse it may peel and form pockets but at least plastic won't rust!

Factory seam sealer and material they use to keep the metal rust free behind the plastic liner is doing well so I hate to mess with that ..

In my other readings online regarding soundproofing it seems like the first line of defense is the killmat or dynamat type stick on product made of foil backed self stick butyl rubber.

I have more than enough of that to do the entire car but in further reading it seems as though the other thing that may need to be added in certain areas is a waterproof closed cell foam to decouple transmitting sound and the putting mass loaded vinyl over that for the ultimate in sound proofing ...

While that may be the ideal from a sound deadening standpoint , I'm wondering if most of the sound deadening can come simply from the addition of the self sticking rubber itself because truthfully in the door panels I'm not sure that there is enough room to put all that stuff between the door card and the interior metal structure of the door and still have the door card fit back on

I don't plan on sticking anything to the inside of the outer door skin thinking that it may cause rust just in the same manner that the factory foam piece on the inside of a front fender causes rust .... I don't want rust.

it was interesting to read somewhere that closed cell foam / foam itself does not deaden sound.... I'm not sure exactly why that is because it seems counterintuitive but that's what I read ( the same site selling sound deadening products recommended Mass loaded vinyl on top of the closed cell foam to do the actual sound deadening... maybe they they are just trying to sell more stuff ?

Of course going whole hog also adds a lot of weight to the car because Mass loaded vinyl weighs 1 lb per square foot... that would be on top of the half a pound of per square foot of kilmat... I imagine closed cell foam is fairly light but I don't have a weight on that.

Although perhaps not the most efficient I'm going to put kill Matt down and maybe some carpet Juke under the carpet at least in front to see how much that helps.

I guess not really knowing which areas are closing the most noise it's hard to figure what I should put where....

Ultimately though I would like to keep things as light as possible because of its potential effect on handling and fuel economy as well.

As far as spraying foam inside the car
That is an interesting thought and I had looked into doing that but I think something like that is better suited for Sprinter type vans where you can build walls out with two by fours or similar and spray everything in between with foam and cover everything up with paneling ... not really super easy to do that in a car and I'm not exactly sure if that foam deadens sound but it seems like it should...

While the modifications are somewhat expensive to do , it's overall much more cost-effective to do that than to buy another vehicle which has to be maintained, fixed, insured Etc plus I doubt any other vehicle would be getting 50 miles per gallon on the highway so hopefully a few mods to the old wagon would be the best bang for the buck...

As a side note and I know it sounds crazy I thought about buying one of those Chinese diesel heaters for the car because I have spent a fair number of nights sleeping in the car after a long run and I hate waking up in the morning ( or earlier) freezing cold...

I did get my sound mat rollers in so l may start tinkering with sound proofing shortly ....
 

Andyinchville1

Veteran Member
Joined
Apr 7, 2016
Location
Virginia
TDI
2003 Jetta TDI wagon, 5 sp, 226K miles
Hi All ,

Thanks for the replies and input...

Outwardly the car is not super loud interior wise ... until I ride in my dad's
Buick Lesabre.... then comparatively my car is very loud ....

Actually when driving and talking hands free using the speaker phone it is hard to converse ... mainly difficult for me to hear the phone even with the phone at high volume the phone is stuck on t I ed windshield mount fairly far from me (blue tooth earpiece is doable but volume has to be fairly high and I stick a earplug in my other ear to hear It better ...).

Ultimately for convenience a n.v d fatigue resistance over the hours spent driving that is my main reason for soundproofing the car.

I agree with the ideas about not making potential areas where water can collect ... i.e. undercoating where the undercoating may form pockets for moisture to collect and cause rust ... I imagine most undercoating failures are caused by inadequate surface preparation or faulty products but I really don't want to open a can of worms either so I'll probably hold off on spraying the undercoating directly behind the wheel wells on the actual metal but rather simply spray the undercoating on the plastic liner itself.

Factory seam sealer and material they use to keep the metal rust free behind the plastic liner is doing well so I hate to mess with that ..

In my other readings online regarding soundproofing it seems like the first line of defense is the killmat or dynamite type stick on product made of self stick butyl rubber foil type product.

I have more than enough of that to do the entire car but in further reading it seems as though the other thing that may need to be added in certain areas is a waterproof closed cell foam to decouple transmitting sound and the putting mass loaded vinyl over that for the ultimate in sound proofing ...

While that may be the ideal from a sound deadening standpoint , I'm wondering if most of the sound deadening can come simply from the addition of the self sticking rubber itself because truthfully in the door panels I'm not sure that there is enough room to put all that stuff between the door card and the interior metal structure of the door .

I don't plan on sticking anything to the inside of the outer door skin thinking that me cause rust just in the same manner that the factory foam piece on the inside of a fender causes rust.

it was interesting to read somewhere that closed cell foam itself does not deaden sound.... I'm not sure exactly why that is because it seems counterintuitive but that's what I read ( the same site selling sound deadening products recommended Mass loaded vinyl on top of the closed cell foam to do the actual sound deadening..

Of course going whole hog adds a lot of weight to the car because Mass loaded vinyl weighs 1 lb per square foot... that would be on top of the half a pound of per square foot of kilmat... I imagine closed cell foam is fairly light but I don't have a weight on that.

Although perhaps not the most efficient I'm going to put kill Matt down and maybe some carpet Juke under the carpet at least in front to see how much that helps.

I guess not really knowing which areas are closing the most noise it's hard to figure what I should put where....

Ultimately though I would like to keep things as light as possible because of its potential effect on handling and fuel economy.

As far as spraying foam inside the car
That is an interesting thought and I had looked into doing that but I think something like that is better suited for Sprinter type vans
 

berks_tom

Veteran Member
Joined
Jan 23, 2006
Location
Birdsboro, PA
TDI
2013 Passat TDI SEL; 2006 Jetta TDI, pkg 0, DSG
I remember reading a thread some time (over a year) ago, where someone had completely covered most of the interior metal surfaces of the car with soundproofing material. Including the floor under the carpets, under the rear seats, the inside of the door skins, the roof above the headliner, and the trunk-- including the hole for the spare tire. I forget the details regarding the wheel wells and the firewall, but I'm sure something was done there as well. He used something that looked like sheets of thick, black, adhesive-backed material that he cut to fit. IIRC- the process was time consuming and not cheap, but he got impressive results.
I tried to search for the thread here and could not find it. I don't look there often, but it's possible it was over on VWvortex.
 

Andyinchville1

Veteran Member
Joined
Apr 7, 2016
Location
Virginia
TDI
2003 Jetta TDI wagon, 5 sp, 226K miles
I remember reading a thread some time (over a year) ago, where someone had completely covered most of the interior metal surfaces of the car with soundproofing material. Including the floor under the carpets, under the rear seats, the inside of the door skins, the roof above the headliner, and the trunk-- including the hole for the spare tire. I forget the details regarding the wheel wells and the firewall, but I'm sure something was done there as well. He used something that looked like sheets of thick, black, adhesive-backed material that he cut to fit. IIRC- the process was time consuming and not cheap, but he got impressive results.
I tried to search for the thread here and could not find it. I don't look there often, but it's possible it was over on VWvortex.
Hi

Yes , the kilmat I got off amazon is the thin black self adhesive sheets with foil on one side and adhesive on the other . .

I think it's supposed to help alot BUT other materials may be needed as well ... like juke padding under the carpet etc...

I'm still learning because I only want to pull stuff apart once.

I bought 3 boxes of the sheeting mentioned above .... I think each box does 36 sq ft.
 

Nuje

Veteran Member
Joined
Feb 11, 2005
Location
Island near Vancouver
TDI
2015 Sportwagen; Golf GLS 2003; 2016 A3 e-tron
In parting out a car, I took off all of sound-deadening off the firewall and under the front seats; I put a layer of it underneath the Golf's spare wheel cover and was quite impressed with what an impact it had on noise level at highway speed, particularly with the rear seats down.
 

tdihopeful

Well-known member
Joined
Oct 23, 2008
Location
California
TDI
03 2dr 5sp Golf
There Nuje's experience suggests that much noise comes from one source in that instance the wheel well area. I don't remember my Golf having been so loud as to be distracting or like you're describing Andy though a different car. It seems that you're thinking the matter out thoroughly and you're sure to have very good results. I don't know if this would work for testing various soundproofing materials combinations but there is probably a phone apps that measure decibels. Make a little apparatus like a shoebox with the different materials/combinations lining it throw youre phone in it with the noise measuring app and use a consistent source of sound maybe a stereo or smoke detector and see what you get. Just an idea.
 

drucifer

Veteran Member
Joined
Dec 21, 2013
Location
fredericksburg virginia
TDI
2004 jetta sw tdi pd
Actually when driving and talking hands free using the speaker phone it is hard to converse ... mainly difficult for me to hear the phone even with the phone at high volume because the phone is stuck on the windshield mount fairly far from me (blue
Integrate your phone with the stereo.
Your dad''s Buick and the wagon are two totally different animals. You wouldn't expect the wagon's fuel mileage from the buick. Why do you expect the ride in the wagon to be as quiet as buick.
 
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