2003 W210 E320 Cdi estate rear suspension noise...has anyone ever fixed this?

[carswaps]

Hi all,

I,ve got a 2003 E320 CDi estate (W210 I think or is the S210 the estate?)
Anyway have the usual clonk/thud from the rear suspension (its worse on the N/S)
I have changed both anti roll bar links - still the same , Both Shock top rubbers - still the same.
Just had the rear front subframe bushes done and its still the same!
Both rear shockers look good with no leaks and all the other arms bushes also look ok with no apparent movement.
I am thinking of replacing the speres next but from the sound of the noise I,m sure it won't cure it?
Any ideas guys? seems all W210 estates suffer with this at sometime so I,m sure someone must have fixed it?
Thanks for any advice.
Steve

 

[GordonTarling]

Maybe take the car to an Indy who knows these cars and see what he can find?

 

[rallen]

I am not sure what the "usual clonk" is . I had a very persistent and weird problem that my mechanic took two test drives and a lot of insistence to believe, and once he believed me he knew the problem immediately. The problem was clanking noises from the rear of the car (suspension maybe) when I accelerated or decelerated suddenly. Apparently it was not the propshaft or driveshafts or anything like that, but some rubber stops on the under and sides of the car associated with the suspension. Maybe it is something like that with you too?

 

[rpe2]

As above, rear subframe bushes.

 

[_Taz_]

just to add, my old W210 had exactly the same problem...

I changed all the rear bushes, then realised there is one that is integrated into the lower part of the SLS rams ( they look like shocks, but aren't )

basically the lower part has 2 bolts that fasten to the wishbone, but nd the bit that i found on the OSR was that the piston has a ball joint at the bottom, it was this fitting that was worn ( it has 2 bolt holes cast into it )...

I ended up settling for the thumps.. but traded up for a W211.

Changing the rear spheres made a massive difference, but the ****** knock was still there !

 

[bigasotonuk]

Hi,
Were the rear sub frame bushes noticeably worn? As I was told that these hardly wear at all and it was the front ones that most commonly failed, IIRC there is also a small bush that is fitted to the back of the hub NEAR the lower shock mount, which commonly fails as well.

 

[_Taz_]

Hi,
Were the rear sub frame bushes noticeably worn? As I was told that these hardly wear at all and it was the front ones that most commonly failed, IIRC there is also a small bush that is fitted to the back of the hub NEAR the lower shock mount, which commonly fails as well.

Hi bud, from memory, 2 of the front "rear subframe" mounts were both shot..

I think they are oil filled, as they were bone dry & torn... the new items from MB were definitely filled with something...

i did the rear "rears" simply because I had started These are massive items and were fine, but I changed them.

I only ever saw the SLS ram bottom ball joints that looked suspect, certainly the OSR had a bit of play, but as the rear is multi-link, I couldn't see anything else that was adrift when I used a pry bar.

The spheres were knackered & had the classic guiness signs... ( one had partial pressure, but not much when I drilled both prior to disposal ).

HTH

 

[Frontstep]

If you look in your sls reservoir, front right under bonnet see if the fluid is black its a good sign of defective spheres.
It is hard to determine knocks over the internet.

 

[carswaps]

Just an update on this for others who may have the same problem.

I have changed the spheres today, fitted a new filter in the reservoir then bled the system by disconnecting the self level actuator arm and manually operating the self level system up and down.
At first not much happened then after 5-10 minutes the car started to lift, at this point I stopped the car, checked the reservoir level and added more fluid.
Re started the car, up and down again then re attached the actuator arm.
Went for a drive and ?????? No change still clonking :dk:
Back on the ramps, more up and down, more fluid added as it took a little more.
Back out for a drive and still the same!
Had a cuppa whilst sitting looking at the back end and I thought it looked a little low.
Back on the ramps, adjusted the actuator arm from A: the lower hole to B: the upper hole (Not sure if it should have been in B all along?) and the last thing I did was unbolt both lower shock mounts (2 x 16mm bolts and nuts on each side) greased and re torqued.
Went for a drive and ?????
Cured no noise at all :rock::rock::rock:

 

[wportre]

I know this is an ancient thread but so are these cars now and they all have this issue. And this tread comes up a lot on searches. So, for posterity. I can confirm (by doing the 2 things separately) that the OP's change of setting in the ALS was the cure, not the lower strut attachments.

I have eliminated a lot of causes, including taking half the interior apart to replace the bushings at the top of the struts.

My ALS was already in the higher hole but I could diagnose that there was no initial load on the struts with the car empty. I've owned the car basically from new but maybe the wrong replacement springs found their way in there or something (they break given all our speed bumps). Anyway, I thought about this and with the spheres unpressurised then over a depression (where my thump was occurring) a vacuum would occur in the struts. That accounted for the gentle thump (rather than harsh clank) noise.

A lot of rust down there but by breaking out the link arm (ball joint either end with plastic "females" on the link: best done on a warm day) I was able to free the centre 10mm adjustment nut. By extending the arm a surprising distance I could pressurise the struts (slightly higher ride height and lower fluid level, with the spheres now part-full). That confined the thump to only deep depressions so I am confident I have a diagnosis.

I'm slightly alarmed to have made a significant adjustment and have some measuring and calculating to do to reassure myself I am not overpressuring the struts. The design load is over 600kg, 300kg per strut so in the short run I am certainly OK. But in the long term I am concerned that my car seemed to be set up to have no preload on the struts (unless the springs are wrong, as I said).

Anyway, anyone keeping one of these old girls on the road and being driven crazy, check the preloading on the ALS.

 

[wportre]

I should add: eliminate spheres as a cause before doing this: ruptured membranes will create the same vacuum/rebound noise. They also turn the struts into rods and the last thing you want to do in that situation is transfer more weight onto them. The spheres can be tested (dismounted) by feeling for the membranes with a blunted thick-gauge wire or similar. They fail reasonably regularly so as other threads say, they are a good place to start with this problem.

ALS = SLS.

 

[HDR17]

I should add: eliminate spheres as a cause before doing this: ruptured membranes will create the same vacuum/rebound noise. They also turn the struts into rods and the last thing you want to do in that situation is transfer more weight onto them. The spheres can be tested (dismounted) by feeling for the membranes with a blunted thick-gauge wire or similar. They fail reasonably regularly so as other threads say, they are a good place to start with this problem.

ALS = SLS.

I recently purchase a 2001 E320 Wagon (US) and the rear end was supper floppy with a loud clunk. I replaced the spheres and they were definitely shot and the ride is more precise and generally good except that I still have a slight clunk sound in the rear end over bumps.. Car is well taken care of interior and outside but the clucking is hard to tell if its the rear hatch, or something else. I even replaced the sway bar links.. got slightly quieter but not gone, but wondering about this procedure you and previous poster noted about the level adjustment.. Would be great if a photo with "A" and "B" location are posted and precise description of the procedure to balance everything out since I raised and lowered the back till I got the car to be even/level with the front - meaning the bottom of the car is level. One final comment, not sure if relevant, but during the replacement of the balls and filling/flushing my reservoir, I accidentally had the level lever up so that it tried to raise the car to the highest point and went up till I heard a "screeching/screaming" sound and then I had to bring it back down. Hoping that didn't cause any permanent damage to any component. Currently no leaks from the rear shock/struts. Thanks for any suggestion.

 

[wportre]

I recently purchase a 2001 E320 Wagon (US) and the rear end was supper floppy with a loud clunk. I replaced the spheres and they were definitely shot and the ride is more precise and generally good except that I still have a slight clunk sound in the rear end over bumps.. Car is well taken care of interior and outside but the clucking is hard to tell if its the rear hatch, or something else. I even replaced the sway bar links.. got slightly quieter but not gone, but wondering about this procedure you and previous poster noted about the level adjustment.. Would be great if a photo with "A" and "B" location are posted and precise description of the procedure to balance everything out since I raised and lowered the back till I got the car to be even/level with the front - meaning the bottom of the car is level. One final comment, not sure if relevant, but during the replacement of the balls and filling/flushing my reservoir, I accidentally had the level lever up so that it tried to raise the car to the highest point and went up till I heard a "screeching/screaming" sound and then I had to bring it back down. Hoping that didn't cause any permanent damage to any component. Currently no leaks from the rear shock/struts. Thanks for any suggestion.

Based on my experience, the screeching is a PRV in operation. Doing exactly what you did (I looked like a concours winner at a San Juan jackup competition) I did no damage. Replacing the spheres as you did is almost like wiper blades: just something you do with a new-to-you car.

Unfortunately I have pretty well given up with my left-side knock having established it is not a safety issue. I am stumped after replacing spheres and front sub-frame mounts (probably something you should do. Butcher's work: no finesse or tools beyond a spare jack a HEAVY hammer and cold chisels), and strut upper rubbers (horrid job). Also having checked over everything else eg strut lower mounts etc. And raising the ride a bit using the fine adjustment you can do (I needed to take out the whole link to free it in the UK climate.)

For a while I convinced myself it was an airlock but bleeding (and time) didn't fix it. These cars are getting old now but are not classics yet: I just look at the thump as part of the patina.

 

[wportre]

Oh and the star socket. What the hell MB were thinking on those things I have no idea.