EauRouge Posted January 25, 2020 Share Posted January 25, 2020 Hi all. I'm a noob here obviously. lol. I'm enjoying my new (to me) 2008 leggy but it was modified by the previous owner and is very noisy inside. It goes like a bat out of hell but on long road trips the noise is intolerable. I've been looking at some options for reducing cabin noise and strangely I can't find anything about it here. Unless I'm missing something and I have searched. Anyway, besides the obvious hood, doors, floor, trunk, and head I'm seeing that replacing the door seal with a newer/thicker one is supposed to be a very effective first step. I'm wondering 1) if anyone has done this, 2) what are the specs of the OEM seal so I can get a proper replacement, 3) has anyone else done any noise reduction on their car? What brands are suggested? How effective? Thank you all in advance and I'm happy to have found this forum. Link to comment Share on other sites More sharing options...
Chocoholic005 Posted January 25, 2020 Share Posted January 25, 2020 What kind of noise is bothering you? Outside noise? Exhaust noise? Rattling/low frequency noise? Link to comment Share on other sites More sharing options...
Enlight Posted January 25, 2020 Share Posted January 25, 2020 (edited) I don't know about door seals, but my understanding is that much of the noise is transmitted through vibration in the sheet metal acting much like a drunk drum. For example, consider the area where the spare tire is located. It is also located right by the mufflers - this area will have a lot of resonant sound. A website some people on this forum have used in the past is SoundDeadenerShowdown, but the guy retired last year and his website is about to expire in the next couple days, I believe. I would hop on there an glean what information you can while it's still there. You just reminded me to download their website. Edit: Spelling Edited January 25, 2020 by Enlight muFreight.co A JDM Container Sharing Service from Japan to NYC Website | Instagram | Email Bessie II's Thread Link to comment Share on other sites More sharing options...
EauRouge Posted January 25, 2020 Author Share Posted January 25, 2020 What kind of noise is bothering you? Outside noise? Exhaust noise? Rattling/low frequency noise? Well, basically the road noise - a combination of tires, engine, wind and other vehicles. Link to comment Share on other sites More sharing options...
EauRouge Posted January 25, 2020 Author Share Posted January 25, 2020 I don't know about door seals, but my understanding is that much of the noise is transmitted through vibration in the sheet metal acting much like a drunk. For example, consider the area where the spare tire is located. It is also located right by the mufflers - this area will have a lot of resonant sound. A website some people on this forum have used in the past is SoundDeadenerShowdown, but the guy retired last year and his website is about to expire in the next couple days, I believe. I would hop on there an glean what information you can while it's still there. You just reminded me to download their website. Thank you. I'm on it. Link to comment Share on other sites More sharing options...
outahere Posted January 26, 2020 Share Posted January 26, 2020 (edited) ...I've been looking at some options for reducing cabin noise and strangely I can't find anything about it here. Unless I'm missing something and I have searched. Do a search in the Interior/Audio sub-forum and you will turn up dozens of threads about sound deadening and noise reduction. Start by searching for "noise". https://legacygt.com/forums/search.php?searchid=22007034 Also take a look at this Sound Deadening FAQ: https://legacygt.com/forums/showthread.php/sound-deadening-faq-7036.html?t=7036 Edited January 26, 2020 by outahere Link to comment Share on other sites More sharing options...
EauRouge Posted January 26, 2020 Author Share Posted January 26, 2020 Do a search in the Interior/Audio sub-forum and you will turn up dozens of threads about sound deadening and noise reduction. Start by searching for "noise". https://legacygt.com/forums/search.php?searchid=22007034 Also take a look at this Sound Deadening FAQ: https://legacygt.com/forums/showthread.php/sound-deadening-faq-7036.html?t=7036 Thank you. Link to comment Share on other sites More sharing options...
08SpecB_DE Posted January 26, 2020 Share Posted January 26, 2020 Look for the source of the noise. It could have upgraded, stiffer mounts that increase nvh, or an engine or trans mount is bad and causing excessive vibration in the cabin. Flat spots on tires can make for a very noisy ride as well. If it's just air coming in from a closed window, replacing the door seals can solve this problem. Link to comment Share on other sites More sharing options...
EauRouge Posted January 27, 2020 Author Share Posted January 27, 2020 Look for the source of the noise. It could have upgraded, stiffer mounts that increase nvh, or an engine or trans mount is bad and causing excessive vibration in the cabin. Flat spots on tires can make for a very noisy ride as well. If it's just air coming in from a closed window, replacing the door seals can solve this problem. Thanks. I was driving today and noticed that the engine noise does seem to come in right through the windshield. Also running my fingers along the window edge I could feel air coming in at just 40 MPH. Those will be my first areas to address. I wonder, do you have any suggestions for door seal replacements? I've seen people say get thicker ones which is fine but how thick and which clips would I get? Link to comment Share on other sites More sharing options...
Enlight Posted January 27, 2020 Share Posted January 27, 2020 I've never heard of thicker door seals so I did some light googling and found this . He inserts poly foam rope into the existing door seals to fatten them up which should also result in a tighter seal. It's a pretty neat idea I haven't encountered before. I might do this myself at some point. Whereabouts in New York are you? muFreight.co A JDM Container Sharing Service from Japan to NYC Website | Instagram | Email Bessie II's Thread Link to comment Share on other sites More sharing options...
Nonamedude Posted January 27, 2020 Share Posted January 27, 2020 The problem with trying to add thicker door seals is that we only have half doors. One reason subaru moved away from that was inherent noise from the design. No matter how thick you make seals, the window can only exert so much pressure on it. Coming from my civic it doesn't seem so bad. I think finding out what was done to your vehicle would make a big difference. Is it a legacy gt, 3.0, 2.5i? Stock exhaust? Do you have a roof rack (mine was making a heck of a noise, enough that after purchase I thought it was a problematic engine noise). Does it have the stock intake? On my turbo, removing the milk jug resonator and an aftermarket turbo inlet increased noise substantially that can sound like a whine at 80mph from the front right of the vehicle. Lots of options. Check out DIYMA (mobile audio forum) for sound deadening. You can get real technical. Don't just dynamat the entire floor. Link to comment Share on other sites More sharing options...
lilredwagon Posted January 27, 2020 Share Posted January 27, 2020 In one of my previous cars, I had an issue with the door seals leaking and the interior starting to get mold. So when I got this car (2008 Outback XT), I went around the factory door seals with expanding gray foam tape they sell at Home Depot. I did it for an extra layer of water resistance, and for that it seems to work well, even though I didn't have any evidence that there was a problem with it before. As far as it's effect on the noise, it didn't seem to do much at all. As mentioned, if you look at how the door is designed, they are half doors. I put the foam tape on the lower halves - where metal closes on metal, but as far as noise, there's a whole other half of the door for external noise to get in. And it doesn't help that the noisy half (the half with the glass) is closer to your ears also. On my WRX, I put roofing tar on the interior of the wheelwells, and that seemed to help a tiny bit. But I also used sound deadening material inside the doors of that car, and that seemed to help the most. But everything was incremental over the course of 18 years of owning it. By now, the whole car is mostly covered minus the roof. It sounds close to an older BMW. Say, a 2006 era 3 series in terms of interior noise. Link to comment Share on other sites More sharing options...
Nonamedude Posted January 27, 2020 Share Posted January 27, 2020 So remember the basis of this is noise is stopped by mass. Full stop. At least as far as I know nothing magic has come out to stop noise transmission. That's why mass loaded vinyl is so good at stopping noise. The more weight the more noise you stop but at a trade off to performance. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
EauRouge Posted January 28, 2020 Author Share Posted January 28, 2020 I've never heard of thicker door seals so I did some light googling and found this . He inserts poly foam rope into the existing door seals to fatten them up which should also result in a tighter seal. It's a pretty neat idea I haven't encountered before. I might do this myself at some point. Whereabouts in New York are you? Hmm. That is interesting. Thanks. Link to comment Share on other sites More sharing options...
EauRouge Posted January 28, 2020 Author Share Posted January 28, 2020 The problem with trying to add thicker door seals is that we only have half doors. One reason subaru moved away from that was inherent noise from the design. No matter how thick you make seals, the window can only exert so much pressure on it. Coming from my civic it doesn't seem so bad. I think finding out what was done to your vehicle would make a big difference. Is it a legacy gt, 3.0, 2.5i? Stock exhaust? Do you have a roof rack (mine was making a heck of a noise, enough that after purchase I thought it was a problematic engine noise). Does it have the stock intake? On my turbo, removing the milk jug resonator and an aftermarket turbo inlet increased noise substantially that can sound like a whine at 80mph from the front right of the vehicle. Lots of options. Check out DIYMA (mobile audio forum) for sound deadening. You can get real technical. Don't just dynamat the entire floor. Boy, the list is long but yes, Cold Air Intake and upgraded turbo as well as turbo back Invidia exhaust. I think the idea with thicker seals was not really crazy thicker but thicker and more pliant so the window can kind of sink into them. Link to comment Share on other sites More sharing options...
Nonamedude Posted January 28, 2020 Share Posted January 28, 2020 Boy, the list is long but yes, Cold Air Intake and upgraded turbo as well as turbo back Invidia exhaust. I think the idea with thicker seals was not really crazy thicker but thicker and more pliant so the window can kind of sink into them. Ah yea that makes sense. And all of those are going to add noise obviously. I kind of want an exhaust but have heard mixed things about droning on long highway drives. Try to isolate your noise and then go from there I think. It could be as mentioned, that you're getting more than necessary resonance from the exhaust which might be helped with fresh rubber hangers if that's an option and some cld tiles strategically placed on the trunk floor. If you're thinking it's coming from in front of you, try making sure you're not getting noise from the sunroof. If it's coming through the dash and front floor you could add strategic mass. It can be tricky to find the actual source. If you think it's the windshield, inspect the seals and shove some loose foam in the corners and see if that helps. I'm about getting ready to start tracking annoying noises. My driver seat belt buckle squeaks. There's a rattle on one side of the radio. Stuff like that, it's annoying but 4hr drives aren't uncommon for me. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
EauRouge Posted January 28, 2020 Author Share Posted January 28, 2020 Ah yea that makes sense. And all of those are going to add noise obviously. I kind of want an exhaust but have heard mixed things about droning on long highway drives. Try to isolate your noise and then go from there I think. It could be as mentioned, that you're getting more than necessary resonance from the exhaust which might be helped with fresh rubber hangers if that's an option and some cld tiles strategically placed on the trunk floor. If you're thinking it's coming from in front of you, try making sure you're not getting noise from the sunroof. If it's coming through the dash and front floor you could add strategic mass. It can be tricky to find the actual source. If you think it's the windshield, inspect the seals and shove some loose foam in the corners and see if that helps. I'm about getting ready to start tracking annoying noises. My driver seat belt buckle squeaks. There's a rattle on one side of the radio. Stuff like that, it's annoying but 4hr drives aren't uncommon for me. Sent from my iPhone using Tapatalk It's funny but I don't hear the exhaust that much. I was surprised when someone else started it and I was outside. The sunroof seems okay. Never thought of the windshield seals. That's a good idea. I have to figure out a way to measure the temperature in the engine compartment. Fatmat I believe is good to 212 degrees. I think I'll start with the hood as that seems the loudest. Then the trunk. Then the doors. Everywhere (mostly) is saying you only need to cover 25% so I'll do the easiest areas. Link to comment Share on other sites More sharing options...
Nonamedude Posted January 28, 2020 Share Posted January 28, 2020 Yea 25% is key. I put maybe three 6x3" strips on the roof of my civic and it made a crazy difference. Remember that'll only reduce resonance though. It's not the best way for noise transmission. I'd be surprised if the hood was a huge issue, imo pull back the carpet in the front seats and get a small rod or drumstick or something and tap the inside of the firewall, floor panel, and sides of the transmission tunnel. If you get any resonance, then beef up those areas of the inside. If it's still an issue, they make sound deadening materials for the outside of cars, like a tar and similar to what's on the underside already. I'd add some of that to the transmission tunnel, and front wheel wells. Then from there I'd look at adding stuff around the center console. I know of you pull the shift boot you can supposedly hear a lot of noise. Some more material in that area may help. I'm mostly going off what I learned in car audio for dampening and deadening. These are common problem areas on most cars. That coupled with trying to remember what I've seen from the many many hours under my outback. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Nonamedude Posted January 28, 2020 Share Posted January 28, 2020 As I sit in my car right now, check out the cowl panel, the metal under the plastic tray below the windshield. That could be a potential source of noise. You might not want to cover it but if you can locate the precise problem we can figure out a solution. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
EauRouge Posted January 28, 2020 Author Share Posted January 28, 2020 Yea 25% is key. I put maybe three 6x3" strips on the roof of my civic and it made a crazy difference. Remember that'll only reduce resonance though. It's not the best way for noise transmission. I'd be surprised if the hood was a huge issue, imo pull back the carpet in the front seats and get a small rod or drumstick or something and tap the inside of the firewall, floor panel, and sides of the transmission tunnel. If you get any resonance, then beef up those areas of the inside. If it's still an issue, they make sound deadening materials for the outside of cars, like a tar and similar to what's on the underside already. I'd add some of that to the transmission tunnel, and front wheel wells. Then from there I'd look at adding stuff around the center console. I know of you pull the shift boot you can supposedly hear a lot of noise. Some more material in that area may help. I'm mostly going off what I learned in car audio for dampening and deadening. These are common problem areas on most cars. That coupled with trying to remember what I've seen from the many many hours under my outback. Sent from my iPhone using Tapatalk Good suggestions I'll check it out. As I sit in my car right now, check out the cowl panel, the metal under the plastic tray below the windshield. That could be a potential source of noise. You might not want to cover it but if you can locate the precise problem we can figure out a solution. Sent from my iPhone using Tapatalk Is that inside the car? The cabin is the last area I'm going to do if I have to. To do it right I'd have to remove the dash and seats. As fas as the hood, I see it mentioned in the two sites by professional installers. The DIY videos are hit or miss with it. In fact, this guy says 1. Sound Deadening Noise From The Engine Car noise comes from a lot of different places, and one of the most obvious sound deadening a car enginePlaces is the engine bay in fact statistics show that the engine alone accounts for over 40% of the overall vehicle noise especially a diesel engine. If you want to soundproof your vehicle, The Engine is where you should start. Luckily Soundproofing the engine is a simple task that you can do right now, follow these easy steps. That's why I'm looking at the hood. It's easy and 40%!! Heck if I get a 25% reduction that would be great. Link to comment Share on other sites More sharing options...
Nonamedude Posted January 29, 2020 Share Posted January 29, 2020 You also have to remember though that the engine is physically connected to the chassis through the crossmember. They put rubber mounts down there to help dampen noise. Mine are solid because the vehicle is quiet enough imo. If you have the originals they are likely worn out and it can, with a floor jack and effort, change them out. Might be worth a look. The cowl panel being outside the vehicle right in front of the glass. I'm not really sure what you could do there honestly. Yea cabin is going to be effort, but remember that's where you sit! In the end it also becomes a game of effort vs reward. I'd love to have a fully soundproof room and in most of my living spaces reseal interior doors and things like that so I understand! Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
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