Roaring sound coming from back end

ian48 · 05-29-2014, 10:41 AM

I recently swapped out the rear subframe bushings on my 135i, and I was expecting to have a slight increase in nvh. Don't know if this started after the swap or if the sound was just made more audible inside because of it, but the rear end is making a roaring sound that is similar to that heard from large mud tires. It varies with speed and above 40 it starts to overtake the speakers that would normally be perfectly audible.
I've done some research and found that many people who describe this say it is the wheel bearings. I wanted to put it on here to see what all of you think, and if there is anyway to test it other than removing everything to get to the bearing.

TheSt|G · 05-29-2014, 10:45 AM

How many miles on the car?

M3 Subframe bushings properly installed should increase the NVH by ~5%, nothing major in the slightest.

ian48 · 05-29-2014, 10:56 AM

I just hit 61000.
I thought it would be about that much. The increase I got is far beyond 5%

TheSt|G · 05-29-2014, 12:24 PM

Quote:

Originally Posted by ian48

I just hit 61000.
I thought it would be about that much. The increase I got is far beyond 5%

61,000 is really early for a BMW wheel bearing to be going(I just replaced all 4 of a buddy's at 190k).

Ever run aftermarket wheels or spacers? If so, what make and size?

If you jack up the car and grab either one of the rear wheels when it is off the ground, can you make them move in a direction other than rotating?

ian48 · 06-01-2014, 02:49 PM

Yeah that's what I thought. I don't think I've heard of them going bad this soon.

Never have run spacers and still on stock wheels.

Jacked it up and tried moving the wheels and got nothing. Just had the normal suspension movement. How hard should I have been trying to move it?

TheSt|G · 06-01-2014, 06:03 PM

You would be able to feel it with just arm strength.

Hard to diagnose over the net. : /

ian48 · 06-02-2014, 09:29 AM

It really is. I'm going to be taking it to the shop sometime this week hopefully and see if they can figure out what is going on.
I'll be sure to report that experience back to here.

ian48 · 06-25-2014, 11:20 AM

Took the car into the shop suspecting it was the bearings and turns out it was. The right rear wheel bearing was rusted and grinding away. I asked if they had any idea how it happened and they told me that they saw nothing out of the ordinary. They were going in expecting an easy job and were met with that unpleasant surprise.

The sound is now gone for the most part. Might just be my paranoia but it still sounds like it's slightly louder than a when I first got the car but that may just be the new bushings. Still, it's a low hum compared to the roar that it was before.

05-29-2014, 10:41 AM	#1
ian48 Private 11 Rep 64 Posts Drives: 135i Join Date: Jul 2011 Location: Southern Florida iTrader: (0)	Roaring sound coming from back end I recently swapped out the rear subframe bushings on my 135i, and I was expecting to have a slight increase in nvh. Don't know if this started after the swap or if the sound was just made more audible inside because of it, but the rear end is making a roaring sound that is similar to that heard from large mud tires. It varies with speed and above 40 it starts to overtake the speakers that would normally be perfectly audible. I've done some research and found that many people who describe this say it is the wheel bearings. I wanted to put it on here to see what all of you think, and if there is anyway to test it other than removing everything to get to the bearing.
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05-29-2014, 10:45 AM	#2
TheSt\|G Resident Tamed Racing Driver 298 Rep 4,697 Posts Drives: 911, 130is, E39 M5, E36 M3 Join Date: Mar 2008 Location: Outside Philly iTrader: (2)	How many miles on the car? M3 Subframe bushings properly installed should increase the NVH by ~5%, nothing major in the slightest. __________________ 2005 E46 M3 Interlagos/Cinnamon with Sunroof Delete
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05-29-2014, 10:56 AM	#3
ian48 Private 11 Rep 64 Posts Drives: 135i Join Date: Jul 2011 Location: Southern Florida iTrader: (0)	I just hit 61000. I thought it would be about that much. The increase I got is far beyond 5%
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06-01-2014, 02:49 PM	#5
ian48 Private 11 Rep 64 Posts Drives: 135i Join Date: Jul 2011 Location: Southern Florida iTrader: (0)	Yeah that's what I thought. I don't think I've heard of them going bad this soon. Never have run spacers and still on stock wheels. Jacked it up and tried moving the wheels and got nothing. Just had the normal suspension movement. How hard should I have been trying to move it?
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06-01-2014, 06:03 PM	#6
TheSt\|G Resident Tamed Racing Driver 298 Rep 4,697 Posts Drives: 911, 130is, E39 M5, E36 M3 Join Date: Mar 2008 Location: Outside Philly iTrader: (2)	You would be able to feel it with just arm strength. Hard to diagnose over the net. : /
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06-02-2014, 09:29 AM	#7
ian48 Private 11 Rep 64 Posts Drives: 135i Join Date: Jul 2011 Location: Southern Florida iTrader: (0)	It really is. I'm going to be taking it to the shop sometime this week hopefully and see if they can figure out what is going on. I'll be sure to report that experience back to here.
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06-25-2014, 11:20 AM	#8
ian48 Private 11 Rep 64 Posts Drives: 135i Join Date: Jul 2011 Location: Southern Florida iTrader: (0)	Took the car into the shop suspecting it was the bearings and turns out it was. The right rear wheel bearing was rusted and grinding away. I asked if they had any idea how it happened and they told me that they saw nothing out of the ordinary. They were going in expecting an easy job and were met with that unpleasant surprise. The sound is now gone for the most part. Might just be my paranoia but it still sounds like it's slightly louder than a when I first got the car but that may just be the new bushings. Still, it's a low hum compared to the roar that it was before.
	Appreciate 0 Quote