[assclown]

TLDR; attempting to diagnose noise from rear end over bumps at low speed, warm outside

Hello, I've had my H&R coilovers on the car (e92 xi) for over 2.5 years now, and when in the higher tempatures (15C +) I've encountered a noise from the rear end. It's hard for me to describe the noise, but sounds like a compression/expansion and makes a 'wublub' noise both sides. It is not the tires rubbing (275/30) as the noise happens on my winter setup (225/40 square on OEM wheels).

Only happens at low speeds over uneven surfaces. Easily demonstrated when turning into my driveway from the road. There's a 3/4" inch difference in road to driveway height and the car always makes the noise here.

Spoke with a few mechanics locally, they said that the H&R shock itself makes that sound and everything else looks fine under the car. If this was true, then the shock should make the noise when compressed and the vehicle is stationary; but it is dead silent then (no noise). So I find it hard to believe what I'm hearing is a shock issue. In addition they said the shocks are not blown.



I'm leaning towards it being an issue with the rear spring, as the H&R coil over set-up uses a tender spring set-up in the rear (red spring in the pictures) and I believe I might be hearing metal upon metal.

I've taken some pictures for the experts out here to help give a view to the install and have a few questions:

[1] Where the tender spring meets the upper perch, could this be the rubbing noise I'm hearing? I'm pretty sure the upper perch is metal, and the red tender spring is metal.

[2] What is the correct position of the Tender spring? above, or below the rear spring.

[3] Do the rear springs need to be oriented with the text printed on them right-side-up? In the picture they are up-sidedown from this.

[4] What is the logical way of troubleshooting where the noise is coming from? When stationary, and rocking the rear left/rear right side creates no noise.

Thanks for reading..

[e679]

The tender/helper can be put above or below the main spring.

Upside down of the main spring will not cuz any problem

Upper spring perch and tender spring shouldn't cuz any issue also because once your car sit on the ground they will clam very tight.

Did you check all the bushes?

[assclown]

Originally Posted by e679

The tender/helper can be put above or below the main spring.

Upside down of the main spring will not cuz any problem

Upper spring perch and tender spring shouldn't cuz any issue also because once your car sit on the ground they will clam very tight.

Did you check all the bushes?

Thanks for the response.. tender spring position and spring orientation don't matter in this case, H&R has confirmed that since the black spring diameter is same on both ends its fine.

Which, and how many bushings are there to check?

[ajsalida]

Couple of things, I notice no dust boots on your shocks. Over time the shafts/seals can get a little corroded. I would inspect them closely as eventually this will not end well. Clean them off and put some boots on.

Also the upper shock mounts bushing or bolts can be slightly loose, worn out, and/or the top nut on the shock if not tightened up properly. If any of this is not tight and in good shape it will make annoying noises, this is a common problem on BMW RSM's.

[badass335]

Did you figure your issue out?