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This is will probably be my last project which is changing out the hood insulating material and replacing it with this sound deadheading foam/mlv material which will actually quiet the engine unlike the OEM material with is very thin and pretty useless other then protecting the paint from the heat.I can bet putting some kind of MLV/sound mat would make a very noticeable difference
This is will probably be my last project which is changing out the hood insulating material and replacing it with this sound deadheading foam/mlv material which will actually quiet the engine unlike the OEM material with is very thin and pretty useless other then protecting the paint from the heat.I can bet putting some kind of MLV/sound mat would make a very noticeable difference
Agreed. This is what I had in mind though. - my concern with what you are thinking of is whether or not it'll stand up to the heat.
I used this for my trunk lining, and it is pretty damn thick, but I'm thinking of perhaps replacing the OEM thing with this as well:
Worth noting that if you just take the entire piece and stick it on the underside of the hood, the hood won't shut, as it's too thick. So you literally would have to trace the existing flimsy OEM cover, and cut this thing to fit, then it should be fine.
Unfortunately I don't know if this will negatively affect the engine, nor do I know whether or not it'll make a difference, because I would suspect most of the engine noise is going through the firewall at the moment. Thoughts?
The heat shouldn't be an issue honestly other then the adhesive you use,you need to be sure to have good adhesion or the heat will just unstick whatever you glued on. Now for sound inside the cabin, I dont think it will help much, it is more to make the engine quiet from the outside, like you said, the firewall would have to be insulated to reduce cabin engine noise. I insulated the carpets going to the firewall and did add foam and mlv mats where the oem sound deadening was for the firewall. I also stuck closed cell foam in holes in the dash to keep the dash from having opening/holes in it if you know what I mean. After doing so I did notice how much quieter my heater fan ran, it was quit before but now its almost hard to tell its on till you put it on almost full blast.
The heat shouldn't be an issue honestly other then the adhesive you use,you need to be sure to have good adhesion or the heat will just unstick whatever you glued on. Now for sound inside the cabin, I dont think it will help much, it is more to make the engine quiet from the outside, like you said, the firewall would have to be insulated to reduce cabin engine noise. I insulated the carpets going to the firewall and did add foam and mlv mats where the oem sound deadening was for the firewall. I also stuck closed cell foam in holes in the dash to keep the dash from having opening/holes in it if you know what I mean. After doing so I did notice how much quieter my heater fan ran, it was quit before but now its almost hard to tell its on till you put it on almost full blast.
Damn - ok, duly noted. I'm still surprised at how noisy MB vehicles are at idle with the engine running, say versus Lexus cars. I'm familiar with the firewall foam and such as I've had to take apart a bunch of stuff under the dash once, and I was actually pretty surprised at how insulated it was! I don't know why MB cars are so, relatively noise, when compared to their Audi/Lexus counterparts. I wanted to see if I could stick some additional foam in the engine bay in the crevice between the engine and the firewall, but there isn't enough space.
Damn - ok, duly noted. I'm still surprised at how noisy MB vehicles are at idle with the engine running, say versus Lexus cars. I'm familiar with the firewall foam and such as I've had to take apart a bunch of stuff under the dash once, and I was actually pretty surprised at how insulated it was! I don't know why MB cars are so, relatively noise, when compared to their Audi/Lexus counterparts. I wanted to see if I could stick some additional foam in the engine bay in the crevice between the engine and the firewall, but there isn't enough space.
Gak. FWP indeed!
Well if I had the money I would be designing a w204 with a 6.2 4matic and a tesla motor in the back, you get the best of both worlds, electric when you want to save gas and keep it quiet, v8 when you need power and fun... Maybe when I finish my mechanical engineering bachelors I will open my own custom shop.. haha I keep dreaming..
Well if I had the money I would be designing a w204 with a 6.2 4matic and a tesla motor in the back, you get the best of both worlds, electric when you want to save gas and keep it quiet, v8 when you need power and fun... Maybe when I finish my mechanical engineering bachelors I will open my own custom shop.. haha I keep dreaming..
Just like standards in life, it's good to have goals
Thanks! It would appear then that the readings you are getting are pretty identical to mine. It'd be cool if you can get data points at 112, 120, 130, 140, 150kmhr so our speeds can match so we can compare results, or alternatively I can try to get data points at 100-108 as well
That said, I think your vehicle may benefit from the soundproofing suggestions provided by a few of us in this thread
Thanks! It would appear then that the readings you are getting are pretty identical to mine. It'd be cool if you can get data points at 112, 120, 130, 140, 150kmhr so our speeds can match so we can compare results, or alternatively I can try to get data points at 100-108 as well
That said, I think your vehicle may benefit from the soundproofing suggestions provided by a few of us in this thread
I'd love to try those higher speeds, but with fixed speed radars here, I'd rather not get a ticket. If I manage any new data point, I'll definitely share it.
As for trying the soundproofing, I am definitely going to attempt it as soon as I find similar materials to the ones you guys used. The only difference is that the CLK does not have a B and C- pillars but nonetheless, I can still around the doors, the trunk, and the hood. For a 13-year old car, I am still amazed when I'm parked at a light with the car in Drive as I can't hear the engine running and still have to look at the RPM to make sure the engine is ON. It's amazing how much MB spends on NVH R&D. I know from my brother who works in the automotive design industry.
I just wanted to add some very interesting datapoints here since this topic has been top of mind as I think about whether or not I want to buy another car.
On the same piece of road, at +/- one hour of each other (so same weather conditions).
The Genesis G90T 5.0L had the same DB measurements taken by the same device at 130km/hr, 140km/hr, and 150km/hr. If you put a gun to my head and said which car was quieter, I would say at 150km/hr, the G90T was 0.5db on average quieter, but you'd figuratively had to put a gun to my head as the differences were so negligible that it's really difficult to say. At 160km/hr or higher, I think the G90T would win because of the double glazing and also because it seemed that at higher speeds the G90T could keep wind noise out better but this is a GUESS.
Now, this is where things get interesting. I also drove a S550 2017 the other day, on a different highway at a different time, but conditions were similar.
On that road, my 204:
130km/hr 66db
140km/hr: 68db
The S class with Primacy MXM4 RFT tires (Stock)
130km/hr: 63db
140km/hr 66db
So the nod still does go to the S class.
========================
It is still crazy to me a G90T is not any quieter than a W204 because the G90T has double glazing, fancy rims, triple door seals etc...
**NOTE: My measurements in this post were not the same in posts before this one as I have switched phones. Please do NOT compare DB measurements in this post with previous recorded ones.
Last edited by superangrypenguin; 07-30-2018 at 12:50 PM.
Now that I finally have my 2012 C300 4MATIC Sport, I can add some data points. I have the OEM 17" inch rims with Continental ContiProContact All-season tires which date back from 2012.
Engine off, dead quiet = 20-21 db
Engine at idle with it fully warmed up at 80C = 39 db
108 km/h on old asphalt = 68 db
Measurement were taken using a Samsung S7 and the Sound Meter from the Google Play Store.
I really think the quality of the asphalt makes a huge difference because at one point I was driving on newer asphalt that was softer and the noise was reduced but I couldn't take measurements. I can definitely hear the noise coming from around the doors so I will soon be doing what you guys did with the areas circled in cyan/blue. I will report back for sure and we can continue validating data here.
Thanks! Guess your CLK (was it?) is quieter than the C
My idle is around 44db, and interestingly enough, if I rev the engine to 2500rpm while the car is stationary, the car is quieter inside when the hood is OPEN than closed. I was testing this b/c I was bored today. Surprised the F out of me!
Its because the sound bounces off the hood and through the firewall.
I tested putting some engine bay sheets in front of the engine side firewall insulation behine the engine. I used this:
and stuck two sheets back to back and placed them along the firewall horizontally.
I put them in an oven to see if they ignite up to 180 deg c and they don't but they melt a little. So I stuck some of this over the top ( the light one)
There is a significant improvement in engine noise reduction on my noisy C200K. I can hear the feint whirring of the transmission gear and just a light deep muted engine sound
Now that I finally have my 2012 C300 4MATIC Sport, I can add some data points. I have the OEM 17" inch rims with Continental ContiProContact All-season tires which date back from 2012.
Engine off, dead quiet = 20-21 db
Engine at idle with it fully warmed up at 80C = 39 db
108 km/h on old asphalt = 68 db
Measurement were taken using a Samsung S7 and the Sound Meter from the Google Play Store.
I really think the quality of the asphalt makes a huge difference because at one point I was driving on newer asphalt that was softer and the noise was reduced but I couldn't take measurements. I can definitely hear the noise coming from around the doors so I will soon be doing what you guys did with the areas circled in cyan/blue. I will report back for sure and we can continue validating data here.
Yes it does.
And that's where good NVH at the design stage comes in to stop the ingress of the noise from the asphalt to the wheel, to the suspension components, to the chassis and finally the cabin. At each point of sound vibration transfer there needs to be some isolation: think tyre tread design, taller tyre side profile, absorbant suspension bushes, even where on the chassis the suspension attaches. This is hard to do and costs R and D dollars and time.
Mercedes used to do that really well-even a W202 does it better than the W204.
But C-Class of today is the same price or less than C-Class of 20 years ago in Australia anyway, yet there so much more tech in these cars. Where are they cutting costs- well NVH is one area.
Its not just about slapping sound insulation and rubber seals-its taken Mazda the best part of 20 years to quieten down their cars.
And Lexus is not as they were either: the IS 2005-2013 had better NVH than the current IS ( comparing compact sedans here)- I've driven both on the same roads.
Now that I finally have my 2012 C300 4MATIC Sport, I can add some data points. I have the OEM 17" inch rims with Continental ContiProContact All-season tires which date back from 2012.
Engine off, dead quiet = 20-21 db
Engine at idle with it fully warmed up at 80C = 39 db
108 km/h on old asphalt = 68 db
Measurement were taken using a Samsung S7 and the Sound Meter from the Google Play Store.
I really think the quality of the asphalt makes a huge difference because at one point I was driving on newer asphalt that was softer and the noise was reduced but I couldn't take measurements. I can definitely hear the noise coming from around the doors so I will soon be doing what you guys did with the areas circled in cyan/blue. I will report back for sure and we can continue validating data here.
Thanks and as per the other poster, absolutely. Road surface + tire choice is a big factor. I don't want to bore people with tread compound, tread block design etc, but they all play a factor. If the tire can't mitigate the noise, then your vehicle has to. The C300 is well built for its price, but after I tore apart a W222 and a 2019 A8 and 2018 LS500, the insulation is shockingly different to the W204. I still remember the 4" of grey dense foam behind the carpet in the footwell of the A8. I'm not kidding. 4 INCHES of foam. It's hard to insulate a 204 without that stuff.
That said if you do not have staggered wheels, try the Toyo Versado Noir tire. I had the Versado LX tire on my last Audi and it was a really quiet tire. That should help your 204 with respect to road noise. The rest is already discussed in this thread
And that's where good NVH at the design stage comes in to stop the ingress of the noise from the asphalt to the wheel, to the suspension components, to the chassis and finally the cabin. At each point of sound vibration transfer there needs to be some isolation: think tyre tread design, taller tyre side profile, absorbant suspension bushes, even where on the chassis the suspension attaches. This is hard to do and costs R and D dollars and time.
Mercedes used to do that really well-even a W202 does it better than the W204.
But C-Class of today is the same price or less than C-Class of 20 years ago in Australia anyway, yet there so much more tech in these cars. Where are they cutting costs- well NVH is one area.
Its not just about slapping sound insulation and rubber seals-its taken Mazda the best part of 20 years to quieten down their cars.
And Lexus is not as they were either: the IS 2005-2013 had better NVH than the current IS ( comparing compact sedans here)- I've driven both on the same roads.
Interestingly enough having tested a 203, the 204 is indeed quieter than the 203. The 202 is before my time.
I don't think it's just cost cutting here at play. MB has introduced several new models to the MB range as well, and the C has drifted from the luxury oriented luxury sport model to a much more sportier version of the luxury/sport category.
If you told a 202 owner that a 204 would be much more like a 3 series...he'd probably lose his mind.
And that's where good NVH at the design stage comes in to stop the ingress of the noise from the asphalt to the wheel, to the suspension components, to the chassis and finally the cabin. At each point of sound vibration transfer there needs to be some isolation: think tyre tread design, taller tyre side profile, absorbant suspension bushes, even where on the chassis the suspension attaches. This is hard to do and costs R and D dollars and time.
Mercedes used to do that really well-even a W202 does it better than the W204.
But C-Class of today is the same price or less than C-Class of 20 years ago in Australia anyway, yet there so much more tech in these cars. Where are they cutting costs- well NVH is one area.
Its not just about slapping sound insulation and rubber seals-its taken Mazda the best part of 20 years to quieten down their cars.
And Lexus is not as they were either: the IS 2005-2013 had better NVH than the current IS ( comparing compact sedans here)- I've driven both on the same roads.
The biggest problem that has made noise isolation more complex is fuel economy. The best thing you can do to dampen noise is to put sound blocking materials in the right places. Unfortunately that material has a weight cost which can impact your fuel use so you (as in Mercedes) need to make it lighter and less sound proof.
I dont think thrh are spending less but we just aren’t yet seeing leap and bound improvements.
Thanks and as per the other poster, absolutely. Road surface + tire choice is a big factor. I don't want to bore people with tread compound, tread block design etc, but they all play a factor. If the tire can't mitigate the noise, then your vehicle has to. The C300 is well built for its price, but after I tore apart a W222 and a 2019 A8 and 2018 LS500, the insulation is shockingly different to the W204. I still remember the 4" of grey dense foam behind the carpet in the footwell of the A8. I'm not kidding. 4 INCHES of foam. It's hard to insulate a 204 without that stuff.
That said if you do not have staggered wheels, try the Toyo Versado Noir tire. I had the Versado LX tire on my last Audi and it was a really quiet tire. That should help your 204 with respect to road noise. The rest is already discussed in this thread
I forgot to mention that I have 225s in the front and 245s in the back and the tire pressure monitor during my readings was saying 38 PSI in the front and 41 in the rear although I had set them for 33 in the front and 38 in the rear, at cold, last week. Not sure how much the tire pressure will make a difference but I thought I'd mention that.
Just put in the D-ring seal today and yes, it takes out some sound and makes the car nicer to drive. Of course, now I hear the drivetrain more and particularly the road noise on rough pavement (I have 18" AMG wheels and OE Continentals). My next step is to yank out the rear seat bottom and those little upholstered filler pieces between the seat backs and the door and get some more/better sound deadening in those spots. In my car, the remaining noise from the road is definitely coming from the back.
BTW, the D-ring is so nice, inexpensive and easy to use, may put it in my other cars just for fun.
Hi @superangrypenguin. This is a fascinating project and I really enjoyed reading the thread. I saw your last post with the pictures marking where you put the "rubber D type seals" on your car. My issue might not be as demanding as your undertaking has been, but I would just like to reduce the wind sounds that I hear around the front two seats. I imagine that if I just follow the placement of the tubes that I should be good to go? Is it this stuff found here?
Nice, I put the universal weather stripping at the same spots you did, the front doors needed 2 layers since with 1 strip (12mm thick), when I shut the door with a piece of paper in between, I was still able to pull it out. I uses my foam stripping first and then put the rubber strip on top on it which the 3m adhesive on the rubber seems to stick well on the foam. With two layers I am unable to remove the piece of paper which results in a better seal.
I see you didn't add any to the bottom of the doors and there's also the bottom corner of the door that can use some sealing
As you can see, the headlight seal and hood seal connect.
With all this, engine bay tempratures are the same but it seems like the air box stays even cooler now that the ducts are sealed and all the air is forced to go in the intake ducts.
.
Do you have a seperate post on what was was done to the intake hoses? Thx
Do you have a seperate post on what was was done to the intake hoses? Thx
No, I don't but I just used some 3in silicon couplers and 3in aluminum piping I had left from previous projects. I wrapped in it some heat wrap but its more for aesthetics than anything.
Hi @superangrypenguin. This is a fascinating project and I really enjoyed reading the thread. I saw your last post with the pictures marking where you put the "rubber D type seals" on your car. My issue might not be as demanding as your undertaking has been, but I would just like to reduce the wind sounds that I hear around the front two seats. I imagine that if I just follow the placement of the tubes that I should be good to go? Is it this stuff found here? https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
For someone new to this, any other tips would be greatly appreciated!
Glad you're enjoying this thread. I went about it a little bit more discreetly than Itwargssf. My focus was to reduce noise while being as discreet as possible from an install perspective. His sound deadening approach is probably more effective, but IMHO it's also more noticable.
I will say that at this point I have, obviously, decided to move on. The main causes of noise from the W204 which I feel are truly "next" on the tackle list but beyond my pay grade are:
1) Dynamatting the "inside" of each car door
2) Switching to dual pane glass. I truly believe most of the noise/wind noise is caused from the single pane of glass used. I was never able to source dual pane glass on the 204. IMHO if I could have switched to dual pane that would have caused the noise to be cut down tremendously. Over the last year or so, I have driven a few cars and measured their noise levels. The so called super quiet 5 series, as an example, is the same noise level as the 204. When I drove the US specced 5 series with dual pane glass, it was as quiet as the S class.
Interesting tidbits like that made me stop my Maybach project on the 204, among other things
03-11-2018, 04:28 PM
