Puzzling noise, right rear over bumps

[repenttokyo]

I posted last month about a booming or banging noise that I have been hearing from the right rear of the car when I ride over bumps in the road. I had the entire suspension checked out by a mechanic I trust, as well as the rear subframe mounts, and everything was fine with the exception of a ball joint, which I had replaced.

The noise is somewhat lessened now, but it is still there. What else could be loose or banging around back there when I go over a bump? It is a bushing issue perhaps, something that could be missed when doing a suspension check? There is no metallic aspect to the sound at all.

[Tiger]

I can only guess shock and shock mount. Possibly bad spring pad that cause metal to metal contact.

[repenttokyo]

I can only guess shock and shock mount. Possibly bad spring pad that cause metal to metal contact.

my guess as well, but shock mount and shock checked out. Shock is about 2 years old, bilstein sport, and the upper shock mount is also 2 years old. I will however be checking everything again myself because this is really puzzling.

[Tiger]

Did you cut down the shock bumper?

[repenttokyo]

Did you cut down the shock bumper?

I removed the bumpstops when the shocks were installed - is that what you are referring to?

[Black 535i]

I had this as the source of a major PITA noise once and once I made sure it was all tightened up back there the noise went away.

[repenttokyo]

I had this as the source of a major PITA noise once and once I made sure it was all tightened up back there the noise went away.

Excellent suggestion - I will take a look at that this afternoon!

[Tiger]

Yep, bumpstop

[repenttokyo]

I had this as the source of a major PITA noise once and once I made sure it was all tightened up back there the noise went away.

took the jack out - didn't help :(

[repenttokyo]

Yep, bumpstop

they are gone.

[tim eh?]

spare tire? just trying to help guess... might want to check the gas tank straps i dunno man...

[ss2115]

Often its Exhaust system mounts - one missing or banging.

[Paul in NZ]

there is a twelve pack of beer you have forgotten about in the boot(trunk)?

[repenttokyo]

there is a twelve pack of beer you have forgotten about in the boot(trunk)?

i wish it were that simple :(

[ss2115]

there is a twelve pack of beer you have forgotten about in the boot(trunk)?

Surely that would be a rattle rather than a bump though :D

[Paul in NZ]

Surely that would be a rattle rather than a bump though :D

not if they are securley packaged.

[shogun]

I had a kind of metal/metal touching/grinding noise some months ago when driving over bumbs or also when changing directions.
Checked many things, no solution. Till we used a mechanics stethoscope and one person pushed the trunk down and up and the other ones under the car with the st. checking each component, so that was easy to find the source.
Turned out to be one dog bone where apparently the inner parts were touching metal/metal in some situations. Maker Karlyn. Only less than one year in. Replaced it against a new one from Karlyn and now after some weeks it starts to make noise again on the new part.
The other side is an old Lemforder and does not make the sound.

Next ones will be Lemforder for sure, they cost more, but no trouble.
I even checked the torque again, and I do not know what someone could make wrong installing dogbones?

[genphreak]

I've got a pair of Karlyns going well... also have a pair for the e28. They seemed okay, but who knows what'll happen one day, maybe Murphy will come back to play as soon as Monday!

[Tiger]

Yeah, I got that problem too... it was like a groaning sound, thunk sound and click sound only on slow town driving speed. At higher speed, nothing really. I experimented by spraying grease through the ripped rubber boot and it knocks the sound back down to just clicks.

Now that you said Karlyn, I am going to skip it. I might go for the Meyle instead at BMA. These thing are not directeional is it? No up or bottom side?

[Tiger]

I found Lemforder pitman arm for $43.50 each at pelicanparts.com. I will check if there is any other places cheaper...

Update. I did find another online source that has cheaper price but it is Febi (Bilstein company) brand and it is $40 each. I went ahead with the Lemforder at Pelican.

[BMWCCA1]

Still sounds like shock bushings. Two years is not unusual for cheap versions to wear out. You say your tech "checked out" the whole suspension but unless he pulled the rear struts there's no way he could have eye-balled the bushings where they fail. My car's first replacements were from Meyle and wore out very quickly. I replaced them with Meyle Heavy Duty bushings. Compare old and new:

http://i31.photobucket.com/albums/c378/BMWCCA1/DSC_0716.jpg

[repenttokyo]

Still sounds like shock bushings. Two years is not unusual for cheap versions to wear out. You say your tech "checked out" the whole suspension but unless he pulled the rear struts there's no way he could have eye-balled the bushings where they fail. My car's first replacements were from Meyle and wore out very quickly. I replaced them with Meyle Heavy Duty bushings. Compare old and new:

http://i31.photobucket.com/albums/c378/BMWCCA1/DSC_0716.jpg

the bushings drop right into the upper shock mount?

[Tiger]

The bushing is integral with the uppsr strut mount... not replaceble.

[Bob in San Jose]

I agree its the Shock mounts.
Had the same problem and the shock mount looked like the one shown.
You need to pull the shock to see this unless the mount is destroyed bad enough that you can see the damage after pulling the rear shelf.

[repenttokyo]

To replace the shock mounts I need to pull the shock, the spring as well as the rear seat in order to get to the top of the mount, correct?

[Black 535i]

As well as the parcel shelf at the rear. Easy job but air tools help to get the nuts off the shock as there is no way to hold the shaft as you are undoing the nut on the strut. Should not take more than 2 hours with a friend helping.

[e34.535i.sport]

To replace the shock mounts I need to pull the shock, the spring as well as the rear seat in order to get to the top of the mount, correct?


Just incase...

http://www.bimmernut.com/forum/showthread.php?t=35703&highlight=replacing+rear+shock+mounts

[repenttokyo]

Just incase...

http://www.bimmernut.com/forum/showthread.php?t=35703&highlight=replacing+rear+shock+mounts

thanks!

[ahlem]

Tie rod links? I have the same thing and the location where the tie rod attaches to the rear control arm has a wallowed out bolt hole.

[Tiger]

Bilstein shock has a nut on the end so the shaft won't sprin if you use the wrench to hold it. Pretty cool feature.

[BMWCCA1]

Bilstein shock has a nut on the end so the shaft won't sprin if you use the wrench to hold it. Pretty cool feature.
It's actually the shock rod just formed into a hexagon, but most shocks have that. Good luck holding onto that while trying to actually turn the nuts with what will fit on the nut which is usually a hand wrench! Air sure works best, if you have it. ;)

[repenttokyo]

using this great tutorial by e34.535.sport (http://www.bimmernut.com/forum/showthread.php?p=279866&highlight=replacing+rear+shock+mounts), I checked into my rear shock mount situation. The left mounts, where the noise was coming from, displayed tons of shredded rubber, while the quiet right side did not. I am going to replace both sides with Meyle heavy duty, based on the recommendations of BMWCCA1 in that same thread. Hopefully, that will address the problem.