kellens

Hello everyone, I've enjoyed reading posts. I am the proud owner of a C300. I special ordered it after testing various versions of the car. My must have was leather with ambient lights and the air suspension, I think the car should have come standard with those.

All said, this is THE loudest car inside I've ever owned above 45mph. Below that, not so bad. Engine is ok, right what expected and test drove.

There's not a sedan made today that's as loud as the Mercedes C300. There's a wind noise in the upper/front portions of the windows. It shows up around 45 and doesn't go away. In crosswinds it's terrible. It's not the normal wind noise that increases as speed goes up. I took it to the dealer, and they said 'it's a design flaw and part of the car, nothing to fix'. It wasn't present in the test drive cars I was in, but sure enough, it was in the loaner. I mentioned this board, and he checked the seals, and mirror and basically said it is what it is. The tires are also noisy, but I'm going to change them soon. Likely to Michelin Primacy MXV, I know not sporty, but quiet as a mouse, and I don't drive a Mercedes to be zipping around. I buy it to be luxurious and smooth.

ANYONE who has fixed a C300 with wind noise right by the driver and passengers front of the window? I'd truck my car to a dealer if they know what's going on. Anyone mechanically inclined is welcome to chime in.

Another question, if there's a TSB for window seal, or other changes, how would I know?

ManiacGT

There are numerous existing topics on this, just do a search. AFAIK no one has actually found a fix for this yet.

kellens

Thanks, I searched the posts which seem a few weeks old. The noise is louder than if you had a $<20k economy car and cracked the windows or door open a bit. Everyone in the car asks if I have the doors shut.

Somebody smart, somewhere has a fix for this I'd hope.

Any ideas how I'd know when a fix was available? I'm certain I'm not alone.

StanNH

It's not a design flaw, because many do not have any wind noise at all. It's more likely to be sloppy assembly. My own C300, which has certainly had its share of problems, is very quiet and free of wind noise.

Glyn M Ruck

It measures as one of the quietest cars in it's class sold in SA. Something is wrong!

mikbar2

The only problem with ours so far, knock on wood, is the stuttering wiper blades.

Sportstick

First, I would make sure they do a stethoscope test to pinpoint the sound. Someone needs to have the stethoscope with the coned end while you drive and move it around to find the source of the sound. Air leak sound can bounce around a cabin and appear to be coming from a different location. Make sure it really is coming from the door glass area. If the urethane was misapplied around the windshield at the plant, that could create air paths which could cause the sound of turbulence. I've seen this exact condition happen, although it was not a Benz.

I would be suspicious of the doors based on you perceiving it happening on both sides. It's possible, but less likely, that both doors were not properly hung. Also, if you "gun-sight" the doors on both sides, you will see if they were properly installed. Stand at the rear, directly behind the tail lamp on each side and look up along the side toward the front. Compare rear quarter and front fender to door. Is everything perfectly flush? Then stand at the sides and look at the doors in the aperture opening. Are the top edges from the front door to rear door on a continuous line, one not higher nor lower?

A problem across the top of the windshield could possibly produce turbulence perceived sound at both ends. Try these steps and it might help get you closer to a solution. I agree with Glyn (as usual!) that this does not sound like the design intent. However, keep on old assembly plant maxim in mind when a problem is found. "We never build just one of anything!"

kellens

Thank you all so much for ideas. I tried the taping trick and wasn't able to locate the sound. I tried ac on recirculate and standing outside. Good idea for stethoscope. Sometimes when cars pass at low speed to the side, it sounds like they are right there as though the window is open or door not shut. The windows all enter the run the same distance. The seals don't seem warped. There's no seal visible at the top and top sides of windshield which seems normal from other C300s. There seem to be repetitive reports of this sound at this specific area on this and other builetin boards. I'd hope for a TSB or a few solid leads before they pull door panels and create more issues.

floridadriver

You lucked out man! This wind noise issue is a big one and seemingly common. Obviously some with the wind noise, and some not. A fix will come. I know it's a relatively new car, but I'm surprised NOBODY that's reported it has had one with the wind howl fixed. Makes me think at least it's not a design issue, but one of seals, fitting, etc...which means it SHOULD be fixable, once someone finds the source.

c21bill

I have an appointment Monday with my dealer to check on the wind noise and rear bumper cover misalignment. The service writer claims he has a particular mechanic that works on noise issues. I'll let you all know how it turns out. These are the only two issues I have with my car although when it was about 3 days old the keyless entry on the driver door and keyless trunk access quit working. After a few days of frustration, everything started working perfectly and continues to work after 3 weeks of ownership. My wife drove our C300 4matic from Oregon to our CA home this past week and averaged 34mpg for the 600 mile trip. I was pleased to say the least.

puzzled

Please keep us posted. I haven't had this problem but I would not be happy if I dd.

kellens

Good luck! Don't let them try and convince you that these items are 'normal'.

kellens

Well....I took my C in today to the dealer today and they had a tech ride with me in the car. The tech and I took out 2 other new C class, and they all sounded softly the same. I'm thinking it's an inherit flaw. We opened a case with MBUSA. I insisted noise level of wind greater than any car I've ever been in is NOT normal. The tech agreed that it was more wind noise than he thought should be there, but admitted he hadn't been in this W205 much. He said it was more noise than W204 at that area for sure, though the car overall less. I don't know what happens at that MBUSA level, if anything.

I also had them note my bumper step off, and they noted it as the same on all their cars, though agreed, if I wanted it fixed, they could do it under warranty to make it flush.

They said IF I wanted the to start pulling off inside door panels and changing the window and then door seal, and then pull off mirror and change it that they would...but I passed, as have no evidence that this would repair. Has anyone else had this done and it done any good?

c21bill

Well, they've had my car for two full days. The service writer did call yesterday afternoon to ask me to leave the car another day so they could align the rear bumper cover but no report yet on noise issues. Keeping my fingers crossed.

floridadriver

Fingers crossed for you too! What did they give you as a loaner? If a C, any difference from yours?

PeterUbers

Guys... What on earth are they going to do to fix wind noise????

c21bill

For a loaner they gave me a GLK which is pretty decent. The dealer called a couple hours ago and said they nicked the tail light while working on the bumper cover and ordered a new light assembly. (stuff happens). Doesn't sound like they found anything specific concerning wind/road noise so I asked them to look into escalating the issue to MB. I just checked the wind noise poll results and a must say I am disappointed that more folks haven't voted. Come on folks, it only takes a few seconds. The more votes, the more accurate the poll.

c21bill

Stan, on another forum you stated very authoritatively that the noise was due to mirrors and door seals. How did you arrive at that conclusion?

Thanks in advance,
Bill

kellens

I escalated my case to MBUSA, and they act like this is the VERY first they've heard of the issue.

This car has a very focal sound at the front/top of driver and passenger window. Might not be noticed by some, but it's there. It's not there as badly in all of them, some worse than others, but the 2015 C has more wind noise right by the driver and front passengers ears even at it's best than most cars.

They need to come out with new seals or something. MBUSA can't do much. It's up to repeat fixes by the dealer. And if the dealer doesn't see one particular issue, their hands are tied too. I'm hopeful with your car in being fixed, that they try some new seals and such. Maybe replace windshield and side mirror gaskets, and door and side window seals, as all these have helped others in varying degrees of success (I read that on a Russian MB forum which also has a thread about this noise issue in the same area)

PeteInGilroy

I'm no technician, but I too think the problem is with the seals.

floridadriver

Sure sounds like it Pete. As experiment, I used masking take around seals of window/door and mirror and it was significantly improved. Thicker acoustic tape would have probably been better, but didn't want to leave marks.

This issue also seems to increase with car age quickly, and here in Florida with warmer/cooer temp swings, suggesting something rubber that's amiss.

PeteInGilroy

When I drove the car home from the dealer the wind noise was very subtle. Now at about 500 miles, I'm noticing it more. It may have been there all along, and I was just too enamored paying more attention to other things.

I still LOVE this car. This is my first Mercedes and I will always have one in the garage in the future.

I'm going to email my MBUSA contact, who helped me when my car was delayed at the plant.

c21bill

If everyone with wind noise issues would first have their dealer check out their cars and then escalate the issue to MBUSA perhaps they would start taking the issue seriously. They can certainly ignore a few complaints but it would be hard for them to ignore dozens of angry consumers.

HelenR

I just REFUSED my C300 I was waiting for which came in last night, ordered custom, deposit returned. Dealer has been very understanding.

ManiacGT

In the US of course, the market and laws being what they are, rejection is a bit easier. In the UK, we have no such protection and dealers are for the most part pretty poor because of it.