ManiacGT

So I looked into the area where I can hear the odd wisp of wind noise at high speed. I had to take the car to a private road so I could take the car to 80/90+ legally.

I first examined all door seals with talc and they all left good marks to suggest the outer middle and inner seals are fine.

I then looked at where the front windshield side strips finish and the subsequent gaps to the roof rails (estate) and pano glass roof were.

I placed tape along where I felt the wind would flow along the front screen, around the rails, across the gap between the windshield and pano roof as shown in the photo.

I took the car up to 90mph+ for a sustained period and no noise.

I then removed all the tape and did the same run.

No noise other than all around wind noise due to cross winds at high speed.

So I don't believe I have the issue outlined on the forums nor could I enhance the seals or gaps further.

I post this just in case any other owner may feel like trying the same approach with their car if they feel the issue exists for them.

floridadriver

Nice work man!! I had taped the same areas, not as thick as yours but carried the tape across the top of windshield, and didn't notice a difference on mine. My taping around the door and window was the trick.

ManiacGT

I've not tried the door but then all my seals seemed to fit just right. Which areas of the door did you tape, between the glass and frame?

Having said that even at 90mph all I could hear was wind whooshing all over the car and not at the top of the window other than the odd fluttering noise from a cross wind.

floridadriver

I had taped around the entire door to frame, and another piece between window and door. Then drove and pulled off sections. My seals looked ok as well. Interestingly, the tape on the BOTTOM of the door made a significant difference, even though the noise was at the upper/front. With a 20mph crosswind at the coast, the noise obvious at 45mph so I didn't have to get that fast. I had also tried the running the fan on high with doors close trick, and felt air escape from that lower area. I think a gap anywhere in the door can cause noise somewhere else, and jus 1 millimeter or 2 mades a surprisingly large difference.

jolt8631

Which makes me wonder if the issue is door height adjustment being very slightly adrift - that may explain why some cars have it, and others don't.

Be good to do the "talc test" along the bottom seals on cars affected?

rex5

told by dealer that Mercedes Benz USA official position is there is no issue with wind noise on the 2015 C class. I am returning the car. Pretending this is not an issue is beyond deplorable. The wind noise is likely some kind of manufacturing issue at the plant perhaps in addition to design but unless they figure it out soon sales of this car will plummet.

MASSC450

Good work ManiacGT...thank you!

pdp8

There are no manufacturing problems, only designs that can't be reliably executed.

hummerhealey

The European built cars experience this issue much less compared to the US built ones. So you can't rule out manufacturing problems. Also if it was a design problem all cars should have it.

StanNH

How can you return a car? Is this a lease with some sort of opt out provision?

The dealer certainly won't just take back a previously registered car and absorb the depreciation hit ... which is about $5,000. Without meeting the conditions of a Lemon Law case, and wind noise alone wouldn't do it, I don't see how this can be done.

StanNH

Absolutely agree with this. It has to be an assembly problem since, even in the US, many cars do not have this problem. My guess is that it is a very slight misalignment of the doors or seals, which allows air to seep in at speed.

The real problem is not the wind noise, but the apparent inability of MB to acknowledge it and offer a remedy for those cars affected. There should be no need for threads like this to even exist.

pdp8

The point is if you come up with a design that you can't reliably manufacture, its a design problem, not a manufacturing problem, you should have come up with a design that (generally) won't be built wrong - some of your plants getting it right most of the time is not enough.

An old boss of mine had previous job running the workstation business for a large computer company. For them one of the great days in any project was when manufacturing signed off on the design. Manufacturing would't do that until they knew they could reliably build it and would push back hard on the design engineers to get there. Good design engineers don't just toss a design over the wall and say "good luck!".

Of course from the customer perspective it doesn't really matter, it MB's responsibility either way, this is just a bit of a hot button with me, engineers have to design things that can be built / deployed / maintained / operated etc.

floridadriver

^^^ This makes a lot of sense to me.

Couldn't agree more the epic fail is at MB and dealer level not to rapidly acknowledge, and eagerly work on a fix for that customer with an issue, and a more permanent one at the factory.

StanNH

This is the part I just don't get. MB has been on top of serious recall issues, and was quick to inspect early production cars for steering column defects. They were right on top of the defective Continental tire issue, and replaced defective tires immediately. They've addressed emissions control issues, and even acknowledged and fixed all the MB-Tex problems.

Yet seemingly minor issues, that must generate a fair share of complaints from customers are, at least publicly, being ignored. A small cosmetic issue like rear bumper cover alignment should have been corrected months ago, yet most cars are still leaving their respective factories with hit or miss alignment. Severe wind noise should not be an issue at all, certainly not on what is billed as a "baby S-Class," but complaints keep coming in with no factory authorized remedy. Customer service logs complaints, but then does not acknowledge those complaints to owners of the cars who call in. One would think that "We're aware of the problem and are currently working on a fix," would be a more appropriate response.

In the end, it looks like anything other than a major safety or regulatory issue is being left up to the individual dealers to figure out and resolve on their own. That leaves it up to the diagnostic skills of the various service techs to repair widespread assembly gaffes. This is not a good way to foster brand loyalty ... regardless of how good the end product may be.

ranord

My son works for a Chrysler/Fiat dealer & I was talking to him about the wind noise issue. He was not absolutely sure how Mercedes works (he is service advisor). He indicates that most dealer service departments hate this sort of issue as the tech (mechanic) typically try to beat the time estimated for any repair, tsb, recall, etc. As there is not a defined fix....rather a heuristic approach to the problem, service is getting a flat rate which techs are not fond of dealing with & being human beings they also like to fix problems, not create further ill will with customers as most dealerships are graded on our performance ratings & appropriately awarded as you all probably know. Mercedes should be ashamed in causing conflicts with both customer & their dealers... Alas, a no win situation!! My own dealer shop manager was @ best Luke warm in me bringing in my C400 for wind noise & according to StanNH THE BLEEDING SEAT ISSUE which was indicated as not a problem on my 11/2014 build (Mercedes shop Foreman) says not a problem.