Bad Rear Sound

I have a 2000 323i with a strange rear sound, only does it after car sits for awhile. It's like a squeak and scrub sound, at slower speed, and mostly when deacceleration. I've removed brake Rotors and Calipers, checked wheels. Does anyone have any ideas what could cause this, or what I could check.

diff oil?

Checked and replaced diff oil, when speed is above 45 the noise goes away

Originally Posted by Nickaroni22

Checked and replaced diff oil, when speed is above 45 the noise goes away

subframe?

Originally Posted by jasonbimmer

diff oil?

I see you guessing quite a bit lately. Just random words thrown out. Are you posting just to up your post count? C'mon, man. Diff oil? Serious? How is that even a good guess? The guessing has to stop, especially if it's without good experience and/or supporting reasons.

OP, the noise you're hearing is likely your rear shock mounts or POSSIBLY your diff mounts. Do you hear the noises as you go over slow bumps or driveways?

Originally Posted by Nickaroni22

Checked and replaced diff oil, when speed is above 45 the noise goes away

OK more info. Is it likely that the noise goes away 45mph+ because wind/road noise becomes more apparent?

Cliffnotes:

Squeak/rubbing sound at speeds below 45mph and on deceleration.

Have you visually inspected the underside of your car? How's the condition of the sheetmetal which meets the subframe mount (particularly drivers side)?

You have a lot of detective work to do

Originally Posted by E46Mango

I see you guessing quite a bit lately. Just random words thrown out. Are you posting just to up your post count? C'mon, man. Diff oil? Serious? How is that even a good guess? The guessing has to stop, especially if it's without good experience and/or supporting reasons.

OP, the noise you're hearing is likely your rear shock mounts or POSSIBLY your diff mounts. Do you hear the noises as you go over slow bumps or driveways?

diff oil can cause chattering and grinding sound when its low. ask me how I know it because my front diff was low on diff oil and it was chattering and making grinding sound at slow speed. especially after been sitting for awhile and cold.

Originally Posted by jasonbimmer

diff oil can cause chattering and grinding sound when its low. ask me how I know it because my front diff was low on diff oil and it was chattering and making grinding sound at slow speed.

The OP didn't describe a chattering and/or grinding sound. Moot point

Originally Posted by E46Mango

The OP didn't describe a chattering and/or grinding sound. Moot point

couldnt hurt to ask.

OP, your particular year/car model is one of the most (if not the most) vulnerable to the subframe mount failure. Have you had it checked? IIRC the earlier E46s has less beefier subframe bushings too which could also be cause of failure as your rear suspension floats around in rotted rubber...

Perhaps a wheel bearing?

Subframe is something I'll be checking into, the sound does go away after I drive for a bit, even at slow speeds. It's like the first few miles I drive I hear it then it goes away. I'm not a mechanic or anything, but I do know some stuff. I checked bushings and shocks nothing seemed to be an issue there. If its the subframe what exactly would I be looking for.

Could be that the bushings have shrunken when cold and are allowing more play then once you drive and things heat up, the rubber expands just enough to where any noise-causing play is gone. You have to pinpoint what rubber is failed. Given the age and likely high mileage of your car, i'd guess that all of it is in need of replacement. RTABS, RSMS, subframe bushings, swaybar bushings, rear CA bushings and balljoints.

Originally Posted by Nickaroni22

Subframe is something I'll be checking into, the sound does go away after I drive for a bit, even at slow speeds. It's like the first few miles I drive I hear it then it goes away. I'm not a mechanic or anything, but I do know some stuff. I checked bushings and shocks nothing seemed to be an issue there. If its the subframe what exactly would I be looking for.

I tough subframe issue was at all times.. Even worse on sharp turns?

But check it ( your year built is the most known subframe issue.

Which i still can't figure out why BMW Stop the warranty recall 2005/2006.

I believe recall should count based on vin lifetime recall on each individual vin # : so hopefully your issue was addressed.

Yours seems like wheel bearing/diff fluid.. You can lubricate the wheel bearing or get new ones... Also change your fluid on differential ,let's not forget it's solid BMW 12 years old car

Rtab- rear trailing arm bushings, 55$ pair/ most expensive will be labor because tool required is costly and you can Make your own shown on some DIY , search!

Bad one- loose turn, loose feeling on the rear, windy days:even worse!

A kit for rear/ all bushings 600$/
Oem

The car has 197,000 miles, it's been a solid car. It's just gotten to the point where things are just getting wore out. My emergency brake broke a few weeks ago, had to get a spring kit. I thought the noise was coming from that, but I haven't found any signs a rubbing.

I'm pretty sure it has to do with a part making revolutions. Axel or something I have an audio file if anyone would like to hear.

My rule of thumb is: after 9 BMW's,
If i can hear squeak {drive next to retaining wall} like something rotating that needs lubed, look for a driveshaft.
If i hear clunk getting on/off gas, some is ok, slapping noise ,,u joints gone.
BMW's talk to you with various noises before they fail.
Over a million miles of business travel in BMW, I have never walked home. that's why I also drive BMW bike.

So I 'was' thinking e-brake and then you said it broke and you got a kit. Did you install the kit already? If so, I think you've just got to work on your adjustment...which I know is a pitb to do. Easy, but a pain.

If you didn't install it yet, that's my guess also.

On the subframe bushings...I'll say this: my subframe was repaired last year a week before the settlement period ended. They found one cracked spring and I asked them to check the bushings...they'd have been glad to have sold them to me, I know...but they said they were fine.

When I replaced my front sway bar bushings...that reading here made me think they have to have failed...I compared the old (180K miles at least) to the new. Virtually no difference at all. The rubber might have been slightly less resilient, but it was still rubbery.

I think the rear subframe bushings are similarly massive hunks of rubber not likely to fail so badly. Not saying it's a bad idea, per se, just that I think they're probably fine and that based on your sounds, I think e-brake. Squeaking and scrubbing...perfect symptoms of an e-brake in my book.

Did this get resolve?

What was the outcome?

Thanks

"..... only does it after car sits for awhile. It's like a squeak and scrub sound, at slower speed, and mostly when deacceleration ..."

My ten pence worth. Nobody seems to have mentioned half shafts. Universal joints? Split boot? Regreasing?

Maybe water has penetrated a split boot. When left bearings dry out. When warms up grease penetrates and squeak goes away. Deceleration takes the load off the joints.

Can you regrease half shaft UJs? Worth a look do you think?