clanging from rear of c class estate

[muskey]

hi guys
ive a small problem with my 2002 c class 270 diesel estate, namely when i go over a small bump in the road, my n/s/r suspension (self levelling air ride), a "hollow clang"sounds. other than this its fine. any suggestions, possible solutions, all gratefully received,also, see my other post in electronics!
cheers, muskey.

 

[sinewave]

Suggestion - Take it to a Garage!

Solution - New suspension bushes/arms/links etc etc


The fact you are asking usually indicates that this is outside of your DIY skills.

 

[muskey]

no, not at all outside my skills. last car was a p38,so well versed in breakdown procedures. just thought id get a little help from a friendly forum before getting the spanners out. thanks for the help chum.

 

[brucemillar]

C class cars break springs like there is no tomorrow. If its a loud metallic hollow sounding clang/ dong? You may well have a snapped spring.

 

[muskey]

thanks Brucie, ill get under it at the w/end!

 

[BlackC55]

100% a broken spring. Only fit genuine mb springs unless you want to lower.

 

[muskey]

nope. springs are fine, any other suggestions?

 

[Stratman]

Are you absolutely sure?

They often break at the very extremity of the coil, in the spring cup.

 

[sinewave]

no, not at all outside my skills. last car was a p38,so well versed in breakdown procedures. just thought id get a little help from a friendly forum before getting the spanners out. thanks for the help chum.

So I gather despite the above statement you've spent the weekend having a look at the other members suggestions and drawn a blank?

 

[muskey]

So I gather despite the above statement you've spent the weekend having a look at the other members suggestions and drawn a blank?

My original post has obviously upset you and for this I apologise, although.i can't see any reason for your sarcasm and hostility. To reiterate, I am just asking for a little help from a friendly forum. If you feel you can't participate, feel free not to post.

 

[duncanh]

Wow, at last, someone with exactly the same problem as me.

I have had this for 2 years now (c220cdi estate, 2002, 283K miles, self-levelling suspension).

Two years ago I put it in for an MOT, expecting it to fail on the rear suspension. It passed.

18 months ago, a respected Indie told me that it was a broken rear spring (after both driving and examining the car). Both rear springs were intact. (Anyone want a spare pair of rear springs for a W203 with SLS?)

I changed the nsr rear wishbone outer bush (which was badly worn), but the clanging remains.

This years MOT I had it closely examined by the Indie and MOT tester (by the way, it passed the MOT again). They could find no reason for the clanging, finding no appreciable wear anywhere. I changed the rear arb bushes and drop-links, they were slightly worn (I was given advisories on them). Again no change to the clanging.

The 'suggestion' from the indie was to change the rear subframe mounts (but he admitted that there was no sign of play on them). It was the only thing he could think of.

Given the age and mileage (hence the value of the car), I don't want to spend a load of money without more certainty that it will solve the problem.

It may be significant that this is the first post with EXACTLY the same problem as mine, and it also has SLS.

Could this be an indicator of where the problem lies?

I am sure that there are not many C class estates with SLS, so has anyone on the forum got real-world experience of it? Is it the same as the E class?

At the last MOT, they had it on one of the machines that shakes and vibrates the suspension, looking for play. Nothing showed up.

Anyone got any bright ideas?

 

[Beno]

Do you have access to a pit or ramp? If so get underneath and get someone to bounce it and track down where its coming from. As some of the guys have already stated it does sound like a broken spring.

 

[duncanh]

Please allow me to re-iterate.

It is NOT a broken spring.

I have changed both rear springs, I have the old ones in my garage. All 4 are intact.

 

[grober]

Suspension strut mounting bushes? If not a bit of lateral thinking--- perhaps its not suspension related = loose spare wheel/broken/loose mount? Jack rattling about? Rear door moving on its mounts/seals door lock adjustment/door stops required- rear exhaust hitting the underside/ rear skirt / loose heat shield- some exhausts have a rubber buffer on the mount bracket to stop this but they are often not replaced if the exhaust box is changed?

 

[muskey]

Do you have access to a pit or ramp? If so get underneath and get someone to bounce it and track down where its coming from. As some of the guys have already stated it does sound like a broken spring.

Don't think this will work as mine seems to clang, for example, when I go over a speed bump, it seems to be when the wheel comes DOWN. I have had it over a pit and checked all the linkages etc. just now wondering if it could be the srs shocker?

 

[brucemillar]

This will not help the fix.


My C240 Estate occasionally gives a clang. Best described as a golf ball hitting the roof. My indie also confirmed broken spring. It wasn't. It is at the rear and only happens when going over things lik speed bumps at low speed.

I have replaced so many bits I now just live with it. I did suspect the dog guard at one point. That has now been removed from the equation.

 

[Mick K]

Got a c180 estate, had to change to 'get you home' spare on off rear -side the other day. Since replacing spare back into the well I have had the odd clank on sharp bumps. I assume it is the spare not secured properly, but it is in the 'will have to have a look' category so cannot confirm. ! (Not self levelling suspension)

 

[muskey]

Got a c180 estate, had to change to 'get you home' spare on off rear -side the other day. Since replacing spare back into the well I have had the odd clank on sharp bumps. I assume it is the spare not secured properly, but it is in the 'will have to have a look' category so cannot confirm. ! (Not self levelling suspension)

No chief, not the spare as I had the same thought as you, and I've packed around and underneath it with old t shirts, but still get the clang.

 

[duncanh]

just now wondering if it could be the srs shocker?

I have also wondered about the SLS system. Could it be the damper or the sphere? I don't know enough about them to comment.

I also thought about something non-mechanical rattling. So I took out the spare wheel, tools, covers, rear load cover etc, and it still clanged.


What I have not tried yet, but will this weekend, is a short drive with the tailgate open. Only problem is that it will beep at me, but I should still be able to hear the clanging.

 

[grober]

The spheres a have no moving parts afaik just a flexible diaphragm separating the hydraulic fluid from the nitrogen gas- nothing to go clang. There is a level control valve which is usually attached to the roll bar/suspension via lever arrangement there might be some play in the linkage but I would have thought that would show up as level movement? Have you tried giving the exhaust a good wiggle up and down yet/