Noise HELP
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Noise HELP
I have a 2011 E350 cabriolet with 139 k. For some time there has been a cyclical growl or hum from what I think is the front driver wheel area. You hear it most when going less than 40 and changes with speed. I checked wheel play and there was a small amount so I changed the hub and bearing. While it was jacked up the wheel spun smoothly and no noise. However when I drove it there was no change. I don’t see any brake issues. Any help would be appreciated.
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Was thinking about the sound…..it’s more of a wha wha wha. I had checked the rear wheels awhile back and didn’t notice any play 9-3 and 6-12. Would it be possible that it’s a cv axle?
Last edited by jetson; Oct 4, 2025 at 11:11 AM.
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Thx for the reply. I drove it last night and when going 15-20 seems to be when the wah wah sound is most noticeable. I jacked up the rear and checked the axle and cv. There is a slight drip from the shaft seal. I out car in drive while under it and no noise from the rear. I hadn’t considered trans or motor mounts. I haven’t noticed any motor violations or movement. Maybe someone could explain how the mounts are related. There is more tire wear on the inside but no major cupping. Michelin MS tires with 15k and plenty of tread.
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Mercedes e350 coupe
The new mounts helped to align the motor and transmission correctly..eliminating any "play" between the two. Mine was flexing enough (likely the transmission mount) to make the above noise mentioned. And I am still amazed on how much smoother the motor is..and the transmission shift points are now very accurate. The car felt as though it were slightly struggling back when it was making the noise.
I guess?
Mark
I guess?
Mark
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E550 Coupe 2wd (2016)
I second the motor mount(s) as the cause. When they give out they lower the engine, which can allow the motor mount support to hit the top of the motor mounts body, so basically metal to metal.
It can also upset the driveline alignment, and while I can't imagine it would cause vibration or noise, it seems that it can?
Are you familiar with the redneck motor mount test? Pop the hood, put it in drive, hold the brake hard and give it some gas. Maybe 1/4 to 1/2 throttle? Do the same but in reverse. When in drive it'll try to lift the left side of the motor, reverse lifts the right side. If the mounts are good the motor won't move much. I'd be guessing but maybe 1/2"? If the mount is shot the motor will jump up quite a bit, a couple inches, and when you let off the gas it'll slam back down and may even do so with a heavy thud.
Basically, if the mounts are 5 years or older, they're either dead or bobsledding to the grave. The trans mount is cheap and easy to change so just do it at the same time. I changed my motor mounts and it wasn't really a big deal, but it seems each Benz model is different and it could be fairly easy like mine, or a pita. If you're into doing it yourself, look for youtube vids on your exact model/eng so you know what to expect.
It can also upset the driveline alignment, and while I can't imagine it would cause vibration or noise, it seems that it can?
Are you familiar with the redneck motor mount test? Pop the hood, put it in drive, hold the brake hard and give it some gas. Maybe 1/4 to 1/2 throttle? Do the same but in reverse. When in drive it'll try to lift the left side of the motor, reverse lifts the right side. If the mounts are good the motor won't move much. I'd be guessing but maybe 1/2"? If the mount is shot the motor will jump up quite a bit, a couple inches, and when you let off the gas it'll slam back down and may even do so with a heavy thud.
Basically, if the mounts are 5 years or older, they're either dead or bobsledding to the grave. The trans mount is cheap and easy to change so just do it at the same time. I changed my motor mounts and it wasn't really a big deal, but it seems each Benz model is different and it could be fairly easy like mine, or a pita. If you're into doing it yourself, look for youtube vids on your exact model/eng so you know what to expect.
