MondayQB

Hi,

I am driving 2009 C Class (W204) 4matic. It is 2 years old (over 40K miles).

When driving over around 60 mph, I can hear howling noise or wind-hitting like sound, I guess, from back side - rear wheel or back side of undercarriage. It sounds like "Doong doong doong doong." My car is pretty quiet under 60 mph but while driving on highway over 60 mph it makes such sound.

I don't know what I should ask to the dealership. I just wonder if it is common or my own problem. Further, wonder if I could fix it.

Hope to hear good advice or comment. SO ANNOYING ... I really hope to fix it before my warranty period ends.

Thank you for any reply.

Glyn M Ruck

I'm having a hard time understanding the noise. From your explanation it's not wind noise from a mirror or a door seal.

Check the Exhaust heat shields under the car to make sure one has not come loose.

Take the dealer rep/tech for a ride & show them what you mean.

Carsy

I am thinking it could be a bad case of tyre noise from excess scalloping.

I would have it checked out asap as it could be dangerous.Check that your tyres are in good condition.

MondayQB

Yeah ... it sounds like a wind-pounding sound when I drive it rear windows open. However, it is absolutely not "wind noise from a mirror or a door seal."

I have been suspecting tire noise (still stock tires) or belt noise (because I can hear the sound when accelerating it over 60mph - further, now, the sound is coming like from the engine room ... no idea ... I think I am too paranoided).

As you pointed out, if the exhause heat shield comes loose, it might be able to make such sound - which is very similar to the wind sound (relatively low volume) when you drive opening the rear windows?

Niti24

I hate when everytime I take the foreman for the ride, the noise is never heard. Once I start driving alone, the noise comes back. I've been having this same issue going over 60mph. Im going to take it to the dealers and see what they can do.

Carsy

Some cars make strange noises when breaking the sound barrier.

Glyn M Ruck

Does it only make this noise with the windows open?

Niti24

not for me. With the windows closed, ac off and sunroof also closed. I don't know where the noise is coming form but it's more than just wind noise. I feel like it's coming from the engine area.

MondayQB

I performed service B at my vehicle (41K miles). It costs $980 including transmission oil replacement, brake fluid replacement, etc., which are required in the maintenance manual.

My service advisor suspects that the noise issue seems to come from my TIRES: Threads "feather."

According to him, each thread (especially outside) is not worn out in the same manner. (I'll add a picture later). He said it doesn't seem to require alignment. He added he experienced the same issue on his E-class.

He suggested I call MiCHELIN to raise this concern and see what it can do for you. Otherwise, he suggested i live with it until tire replacement.

Hope it will help friends having similar issue.

MondayQB

Small thread issue could make such a lousy noise? I am just wondering ...

Glyn M Ruck

Air pumping noises due to feathered tread can sound like a wheel bearing failing. Which Michelin tyres are you running? I can assure you that PS2's & Exalto PE2's are some of the quietest tyres you can run on this chassis. Conti's are usually the worse for noise SC2 & SC3. The noise usually starts on front tyres. Have you rotated feathered front tyres to the rear or are you staggered?

MondayQB

My tires are stock tires (staggered) - Michelin HX MXM4. Tire feathering is more obvious in the rear tires (outside threads) than the front.

I do some research on this issue and most of people are talking about alignment issue (e.g., toe-setting, camber ...).

MB service advisor said alignment doesn't need to be rendered. But my car is reaching warranty period so I am concerned.

What do you think I have to ask them to check? - Could it be a normal tire wear out due to aggressive driving (i.e., aggressive cornering)? I am not an aggressive driver though. Share your expertise with me.

Thank you.