xCharmCity

I have a W205 C43 and when my engine is cold my car makes a noise when I accelerate and brake. It sounds like a fan is spinning and rubbing against something. Almost sounds like when something is stuck in the spokes of a bicycle tire. It only happens when cold and it doesn't seem linked to engine RPM since the sound happens after I've started to accelerate and brake and gets louder even if I don't build revs. Any ideas? Thanks so much!

blizzard12

Is this the kind of noise you're hearing?

xCharmCity

YES it is very similar it only happens right after I accelerate and right after I brake. And only when the engine is cold. When it happens it only happens for maybe 3-5 seconds. But the second and "location" that the sound is coming from is the same.

blizzard12

Similarly on my car it happened on cold starts only around 50 km/h and only for a few seconds. As soon as I reached 60 km/h or slowed down to 40 km/h the noise was gone. It turned out to be the hanger bearing located under the central console, under the car. The one that holds the drive shaft going from the transmission to the rear differential.
The dealer replaced it and the noise was gone.

xCharmCity

Thank you for your insight! I'll let the dealership know and hopefully they can get it fixed.

blizzard12

It was pretty hard to find the issue as it was only happening on cold and only for a few seconds. The dealership used "chassis ears" to find the source of the noise.
Good luck!

alexasa

iTrader: (1)

Did they say why or if there was something wrong beyond the noise?

blizzard12

No, they did not. Only that it was coming from the hanger bearing which they replaced and the noise stopped.