Wind noise in C400
It is very possible the early test cars of this new model originally included acoustic glass and the reviewers who first drove them were treated to cars in Germany with this feature. This may explain so many positive car magazine reviews specifically commenting on such a quiet ride. It is clearly not the same car that is described in most of the reviews or there are manufacturing issues in the US version of the car. Every loaner I drove and I drove 4 or 5 had the same wind noise on highway driving.
The wind noise is a loud flapping noise that is impossible to miss but it is only present during fast highway driving over 50 to 75 mph. If you do not plan to drive the car on the highway then the car will not have noticeable wind noise. Impressively quiet on side streets and local driving.
It is very possible the early test cars of this new model originally included acoustic glass and the reviewers who first drove them were treated to cars in Germany with this feature. This may explain so many positive car magazine reviews specifically commenting on such a quiet ride. It is clearly not the same car that is described in most of the reviews or there are manufacturing issues in the US version of the car. Every loaner I drove and I drove 4 or 5 had the same wind noise on highway driving.
The wind noise is a loud flapping noise that is impossible to miss but it is only present during fast highway driving over 50 to 75 mph. If you do not plan to drive the car on the highway then the car will not have noticeable wind noise. Impressively quiet on side streets and local driving.
I took out my BMW e89 this weekend as I was convinced this was much quieter in wind noise. As it turned out, there was just as much, if not more wind noise in that, also circa 70mph+ and I worked that out simply because I could hear the wind noise at that speed over the immense roar of the tyres in that car.
I'm not concerned enough about the wind noise to make more of a fuss than have them look at it for me upon its first service (which is 10 months away) or should another reason/issue rise up. While there are several minor niggles with the car, there's not enough to take the whole car in, I'll just have them looked at when convenient.
It is very possible the early test cars of this new model originally included acoustic glass and the reviewers who first drove them were treated to cars in Germany with this feature. This may explain so many positive car magazine reviews specifically commenting on such a quiet ride. It is clearly not the same car that is described in most of the reviews or there are manufacturing issues in the US version of the car. Every loaner I drove and I drove 4 or 5 had the same wind noise on highway driving.
The wind noise is a loud flapping noise that is impossible to miss but it is only present during fast highway driving over 50 to 75 mph. If you do not plan to drive the car on the highway then the car will not have noticeable wind noise. Impressively quiet on side streets and local driving.
The Acoustic glass isn't being offered in North American Builds. It is option code
SA851, and part numbers are A2057251800 And A2057252300.
Maybe it will come, they recently added acoustic glass to special order (spec) for the 2015 E, and there it is for all 4 side windows.
The glass is belong standard in many cars, it's not only quieter, not much more expensive, but also a little lighter which helps CAFE standard meeting.
This might sound silly, but has anyone tried opening/closing their windows at higher speeds? Does it make a difference in the sound?
It would be nice to read that someone has made progress before I obsess on this.
The Best of Mercedes & AMG
This might sound silly, but has anyone tried opening/closing their windows at higher speeds? Does it make a difference in the sound?


Oh well, I finally got fed up with the car and traded it in this weekend. Very glad to be rid of it to be honest. Still plan on hanging around here just for the pure curiosity of seeing what other issues creep up or what resolutions MB has to eventually offer for those with the wind noise issues and more.
I finally had a rain free day and was able to effectively evaluate the noise from the loaner. While still noisier than I anticipated, it does appear to be somewhat better than my car.
Initially I thought it was noisier, but that was due to the rain being whipped around the car at speed.
Last edited by rustycruiser; Jun 4, 2015 at 02:21 AM.
Historically, unlikely a fix from Mercedes. You'll either hear that they 'don't hear it' or 'its normal' or 'its part of the design'. Probably will see new mirrors and minor changes at it's first refresh, until then, it's not a quiet car but can be improved if you're resilient and get the dealer and MB to help you. Easier said than done.
One would think the force of the air rushing by the body of the car would keep it more or less in the closed position.
As far as the door opening on its own....... I am sure glad I have not had any of these type of issues.
I drove with a foreman and he said "sorry, I do not hear anything" even after we switched driver and passenger seat.

My service advice was really nice, and I enjoyed Naruto as her son did.

She asked another foreman to test drive and fix issues for me.
The other foreman identified the wind noise and invited MBUSA to test drive with him. (the issue statement says "case opened and handed off to FTS for an onsite visit", im wondering if FTS means Fc ths sh*t?) Yes, they opened a case with MBUSA and the tech support from MBUSA provided the dealership part numbers on front side glasses - later confirmed they were the ACOUSTIC GLASSES shipped from Germany. Although they said those were to LESSEN the noise not to eliminate, I was really happy at the time because I knew it was hard to get those glasses, while I got them for free and not a single phone call between me and MBUSA. My dealership went through those for me.
There are some good technicians, and certainly responsible ones out there in each dealership, you just have enough luck to meet them. Dealership played a role as well.
I will post an update after I replace with acoustic windows. It's in back order now. Expect first week Sep.
Thanks.
I drove with a foreman and he said "sorry, I do not hear anything" even after we switched driver and passenger seat.

My service advice was really nice, and I enjoyed Naruto as her son did.

She asked another foreman to test drive and fix issues for me.
The other foreman identified the wind noise and invited MBUSA to test drive with him. (the issue statement says "case opened and handed off to FTS for an onsite visit", im wondering if FTS means Fc ths sh*t?) Yes, they opened a case with MBUSA and the tech support from MBUSA provided the dealership part numbers on front side glasses - later confirmed they were the ACOUSTIC GLASSES shipped from Germany. Although they said those were to LESSEN the noise not to eliminate, I was really happy at the time because I knew it was hard to get those glasses, while I got them for free and not a single phone call between me and MBUSA. My dealership went through those for me.
There are some good technicians, and certainly responsible ones out there in each dealership, you just have enough luck to meet them. Dealership played a role as well.
I will post an update after I replace with acoustic windows. It's in back order now. Expect first week Sep.
Thanks.
Very interested to hear your results.
Any advice to get the dealer to get me acoustic side glass?
The problem has nothing to do with door latch or malalignment from previous posts and dealer attempts.
The problem is primarily cars out of Vance.
Very interested to hear your results.
Any advice to get the dealer to get me acoustic side glass?
The problem has nothing to do with door latch or malalignment from previous posts and dealer attempts.
The problem is primarily cars out of Vance.
As I said I did not ask the dealer for acoustic glass; however, I mentioned it exists (not sure if this had been forwarded to the foreman). I do not think i can provide any helpful advice, but try to say some owners had replaced those glasses and please have MBUSA involved and sent FTS to check onsite.. I do not have any misalighment issue from the door.
I just found out it's requiring more minimum force to close my driver side door after I took the vehicle from service. It was addressed earlier and not so long after car's delivery. It is happening again. - Minor and easy to fix.







