Squeak coming from rear

[kumulonimbus]

When I park and climb out of my car, there is a loud squeak coming from what sounds like right around the driver's side rear wheel. If I push down on the rear end and bounce it up and down the same squeak is heard.

After doing some Googling it sounds like it could be a number of things. To narrow it down, I investigated. Being a total noob at this I jacked up the rear, climbed underneath, and didn't know what I was looking at. Brought the car back on the ground, then the squeak was gone!

Of course it wasn't gone permanently. Came back the next time I drove and parked. But I jacked up the driver's side rear again, then brought it back down, an the squeak again disappeared.

I wish I was savvy enough to know what this meant. Is this enough info for anyone to deduce the culprit?

________
edit:
Bilsteins, rear sway bar, rear shock mount, rear strut bar, aluminum rear shock mounts, urethane rear subframe mounts

[Quadrajet]

It may be a bad spot on the shock shaft. When you unload the suspension and set it back down, the car isn't settled enough to get to that point on the shaft. Then when you sit in it, of course it goes down low enough to get to that spot.

I had the same probem with my 318 till I lowered it(new shocks/springs) now no more squeak. Next time you get it in the air, you could shoot some silicone lube up there, I'm assuming your shocks have the "dust sleeves" still, and see if that stops the squeak for a while.

[AndrewBird]

Any other symptoms like clunks or vibrations? Stock bushings, or polyurethane?

[kumulonimbus]

Any other symptoms like clunks or vibrations? Stock bushings, or polyurethane?

I hear clunks and chatter when going in reverse, but I think that's a different issue/unrelated?

I updated the original post to include some stuff that's installed. I think I have stock bushings. Is there an easy way to tell?

[jlevie]

Disconnect the rear sway bar links from the trailing arm and see if the squeak goes away, if it does replace the sway bar bushings and end links. If it doesn't the noise could be from the shocks or trailing arm bushings. To figure out which, disconnect the shocks, remove the springs, and with the sways disconnected move the trailing arms. If the noise is still present replace the RTAB's, otherwise replace the shocks.

[AndrewBird]

I think I have stock bushings. Is there an easy way to tell?

They will generally be colored, like red or white, though some are black, where as stock will be black. Poly bushing also will have sharp, square edges, where as stock will be more rounded.

[ghrays]

Disconnect the rear sway bar links from the trailing arm and see if the squeak goes away, if it does replace the sway bar bushings and end links. If it doesn't the noise could be from the shocks or trailing arm bushings. To figure out which, disconnect the shocks, remove the springs, and with the sways disconnected move the trailing arms. If the noise is still present replace the RTAB's, otherwise replace the shocks.

I replaced all of the rear suspension rubber parts recently, including the sway bar bushings and drop links as well as the RTAB and rear sub-frame bushings, all with OEM BMW rubber parts. I did not grease any of these. After about a month, the rear end is squeaking like crazy when first moving either forward or backward. There is no sound from pushing the rear bumper down and letting it release.

I tried spraying some WD40 silicon spray on the sway bar bushings and drop-links, it helped some, but the creaking sound came back after a few days. I took jlevie's advice and disconnected the drop links from the rear trailing arms and the noise went away. Totally.

So, do I need to remove the sway bar bushings and grease them, and if so with what lubricant? This is not an easy task when the exhaust and rear suspension has already been re-installed and are in the way to some extent. I also may not have installed the drop links correctly in that Bentley says to torque them after the car is in resting position and I tightened the fasteners with the car on jackstands. I also wondered if I installed the sway bar upside down (I took it out for cleaning and re-painting), but I don't think it can go any other way than the correct one.

[AndrewBird]

I don't think you can install the bar upside down. Silicone grease is what is used for poly bushing, not sure if it is safe to use on rubber.

[ghrays]

Unfortunately it was wishful thinking that the creak went away after disconnecting the rear sway bar link brackets from the rear trailing arms. It actually had no effect. the sound seemed to be coming from the outside aspect of each side of the rear seat. I went and pushed on the rear subframe bushing cover plates, and the sound was reproduced. Then I sprayed some silicon lubricant on the joint between the bushing and the cover plate (parts 3 and 4 on the rear axle OEM diagram). The noise was significantly reduced, although not eliminated. I am going to let it soak over night and then try an extended drive tomorrow. If this turns out to of only temporary benefit, I guess I could remove the large furled bolt (#2) and try to cover what I can with grease and re-install the bushing bolt, cover and nut.

[twright]

My squeaking noise was caused by the rear top shock mounts. Peel the trunk side plastic back and listen by the shock mounts. It was real easy for me to hear that was the cause of the squeaking.
New shock mounts and all is quiet.