First post here on the forums, haven't found anything regarding this issue anywhere at all, so I'm writing you all an essay.
I own a 2010 3, and I've had this issue basically since I owned the car. The dealership couldn't recreate it, so they had no idea what I was talking about or what to do to correct it, until I drove them down the street in the car and recreated the noise. At that point, they cocked their heads, shrugged, and I left.
Here's what's going on: While the car is running, and the fans for heat/ac are off, everything is great. Car is quick, has great throttle response, and doesn't make any noise. When the fans are ON, something strange happens.
First off, when accelerating from idle, at roughly 2900rpm it sounds like a belt jumps. It sounds like a bird chirping one quick, loud, chirp. But then that's it. The very second that the chirp happens, the car actually feels as though it's stuttering. as the jump happens, acceleration is stopped. But only for about a quarter of a second.
While driving in fourth / fifth and sitting at around 3k, the chirp happens as well. Cruise on, rpms are still, and the chirp will happen at random.
While shifting, normally the sound will happen just after releasing the throttle to shift to the next gear. In addition, while in gear, anytime the throttle is released after heavy acceleration, it will chirp as well.
I'm a part-time valet in addition to my day job, and I've driven multiple 2010-2011 mz3s both 2.0 and 2.5 that make this noise as well, regardless of it being auto or manual.
If anybody has experienced this at all, please, let me know. I don't have an answer to what's going on, and at this point, I just can't use my heat or ac, so winter and summer are rough.
I own a 2010 3, and I've had this issue basically since I owned the car. The dealership couldn't recreate it, so they had no idea what I was talking about or what to do to correct it, until I drove them down the street in the car and recreated the noise. At that point, they cocked their heads, shrugged, and I left.
Here's what's going on: While the car is running, and the fans for heat/ac are off, everything is great. Car is quick, has great throttle response, and doesn't make any noise. When the fans are ON, something strange happens.
First off, when accelerating from idle, at roughly 2900rpm it sounds like a belt jumps. It sounds like a bird chirping one quick, loud, chirp. But then that's it. The very second that the chirp happens, the car actually feels as though it's stuttering. as the jump happens, acceleration is stopped. But only for about a quarter of a second.
While driving in fourth / fifth and sitting at around 3k, the chirp happens as well. Cruise on, rpms are still, and the chirp will happen at random.
While shifting, normally the sound will happen just after releasing the throttle to shift to the next gear. In addition, while in gear, anytime the throttle is released after heavy acceleration, it will chirp as well.
I'm a part-time valet in addition to my day job, and I've driven multiple 2010-2011 mz3s both 2.0 and 2.5 that make this noise as well, regardless of it being auto or manual.
If anybody has experienced this at all, please, let me know. I don't have an answer to what's going on, and at this point, I just can't use my heat or ac, so winter and summer are rough.
