W211 Rattle from front

[gary87]

I have a rather annoying rattle coming from the front of my S211. The shocks, springs and top mounts have been replaced and there doesn't seem to be any play in anything? Mercedes checked it and said there was no noise they could hear. Me and a mate went round it with a pry bar both in the air and on ramps and everything seems tight/no play. Car has passed two MOT's since the noise started, with not even an advisory.

The noise can only be heard when I go over a bump and even then, it doesn't happen all the time. It seems to come from the left more than the right but if the bump is particularly "bumpy" then I could hear it from both sides?

Anti Roll Bar perhaps? The droplinks for it potentially?

 

[Matt58]

Try the brake disc back plates, took me ages to find rattle. Easy fix with some large washers.

 

[W1ghty]

I have a rather annoying rattle coming from the front of my S211. The shocks, springs and top mounts have been replaced and there doesn't seem to be any play in anything? Mercedes checked it and said there was no noise they could hear. Me and a mate went round it with a pry bar both in the air and on ramps and everything seems tight/no play. Car has passed two MOT's since the noise started, with not even an advisory.

The noise can only be heard when I go over a bump and even then, it doesn't happen all the time. It seems to come from the left more than the right but if the bump is particularly "bumpy" then I could hear it from both sides?

Anti Roll Bar perhaps? The droplinks for it potentially?

Lower suspension arm ball joints are common suspects .

 

[Alps]

check the brake pads also, I had a set come away from its backing plate and rattled around in the calliper, still stopped the car ok, just loose.

 

[Jobsworth]

The antirollbar is fixed to the camber arm via a balljoint pressed into the camber arm. They can give the noise you describe when worn and are very difficult to diagnose. You can peen the disc on the back with a ball pein hammer and it will shut them up for a month or two. At least then you know what it is.

 

[gary87]

The antirollbar is fixed to the camber arm via a balljoint pressed into the camber arm. They can give the noise you describe when worn and are very difficult to diagnose. You can peen the disc on the back with a ball pein hammer and it will shut them up for a month or two. At least then you know what it is.

I have a pair of droplinks here for the ARB, I'll get them changed and have a look at these camber arms.

 

[saff]

I had a knocky-rattle on my 211 when I hit a speed hump or some poor road surface (all to common these days unfortunately). After much searching it turned out to be a broken plastic undertray which clonked against the chassis. I got it secured and blissful silence.

 

[Tommi]

In my 219 it turned out to be arb links and thrust arms, when it was checked by the garage with pray bar everything seemed to be ok but after I took the links off it was obvious what was creating the knok. There was no play in ball joints but the hexagon bit was rounded off as you can see on the photos.