2011 335is Strange Noise From Blower motor?

code85 · 12-20-2015, 01:03 PM

Hey guys and gals

My car currently has about 69,000km. I've had this strange noise when the heater is on since last winter, brought it to the dealership and they couldn't reproduce the noise; typical.

Car wasn't fully warmed nor was it completely cold when the sound happens. The sound, which I suspect is coming from the blower (I can be wrong) makes a high pitched sound when I'm braking. The video confirms that it's not the brakes that are squealing because the squeal is not apparent when the heater is off. This noise is audible at all fan speeds. There is no noise when A/C is on.

The summary of the video.

Video starts off with heater ON, noise is apparent when braking.

I would then turn off the heater, accelerate and brake; no noise

Turn the heater back ON, noise returns.

It's just strange that the noise only happens when I brake.

here's the video of the sound.
[u2b]https://youtu.be/GCzzCYLGvLg[/u2b]

Thank you in advance.

bimmer74 · 12-21-2015, 11:32 AM

Water dripped on top of the blower motor causing some corrosion which makes it squeal in the cold. If you take off the air filter cover near the windshield and look down the left opening, you will most likely see the rust on the top of the blower motor. You can spray some clear silicone lubricant there (not wd40 as it will stink up your interior) or your dealer should replace the motor for you. I fixed it with the lubricant on my 128 and when it also happened on my 335, the dealer replaced it. It is a well known issue and my dealer acknowledged that.

code85 · 02-02-2016, 05:29 PM

Blower motor was replaced by the dealer due to "malfunction".

12-20-2015, 01:03 PM	#1
code85 Enlisted Member 0 Rep 38 Posts Drives: 2011 335is cab Join Date: Feb 2015 Location: Markham iTrader: (0)	2011 335is Strange Noise From Blower motor? Hey guys and gals My car currently has about 69,000km. I've had this strange noise when the heater is on since last winter, brought it to the dealership and they couldn't reproduce the noise; typical. Car wasn't fully warmed nor was it completely cold when the sound happens. The sound, which I suspect is coming from the blower (I can be wrong) makes a high pitched sound when I'm braking. The video confirms that it's not the brakes that are squealing because the squeal is not apparent when the heater is off. This noise is audible at all fan speeds. There is no noise when A/C is on. The summary of the video. Video starts off with heater ON, noise is apparent when braking. I would then turn off the heater, accelerate and brake; no noise Turn the heater back ON, noise returns. It's just strange that the noise only happens when I brake. here's the video of the sound. [u2b]https://youtu.be/GCzzCYLGvLg[/u2b] Thank you in advance.
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12-21-2015, 11:32 AM	#2
bimmer74 Second Lieutenant 9 Rep 212 Posts Drives: 2011 335i xDrive Sedan Join Date: Mar 2008 Location: Massachusetts iTrader: (3)	Water dripped on top of the blower motor causing some corrosion which makes it squeal in the cold. If you take off the air filter cover near the windshield and look down the left opening, you will most likely see the rust on the top of the blower motor. You can spray some clear silicone lubricant there (not wd40 as it will stink up your interior) or your dealer should replace the motor for you. I fixed it with the lubricant on my 128 and when it also happened on my 335, the dealer replaced it. It is a well known issue and my dealer acknowledged that. __________________ 2011 335i xDrive Sedan / 6MT / M-Sport / PPK1
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02-02-2016, 05:29 PM	#3
code85 Enlisted Member 0 Rep 38 Posts Drives: 2011 335is cab Join Date: Feb 2015 Location: Markham iTrader: (0)	Blower motor was replaced by the dealer due to "malfunction".
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