Knocking on n/s rear

[dm250]

Hi all , I have 2005 w211 estate it has a knocking noise on the rear n/s when going over a pump in the road or when hitting a pot hole , have had it checked and there is no visible known problem with the car, but my mechanic says only thing he can think it could be is the air bag , any ideas would be helpful thanks Daren

 

[WG M-B]

Subframe mount? I have changed many on 211's
Worth removing the wheel and having a good looky at the mount on the front of the subframe!!!
Never known an airbag to knock. And when the shocks are shot the rear end becomes very floaty.

 

[dm250]

Hi ,thanks for reply will get it looked at ASAP , the car passed it's mot in November surprised they didn't pick that up !!!!

 

[WG M-B]

They never pick them up. Remember I am only giving you a pointer

 

[dm250]

Thankyou will get it checked out

 

[Major774]

Does the rear use drop links in a W211?

 

[dm250]

Hi all , just an update on the n/s rear knock , now had two mercedes specialist look at my car and they carn't find a thing wrong with the rear suspension , check all bushes rear subframe mounts but still nothing , so I think I will av to live with it and turn the radio up lol

 

[duncanh]

I have the same problem at the rear of my S203 (with self levelling suspension). It has been the same for the last 3 MOT tests, nothing picked up.

It has been suggested that it is the rear sub frame mounts, the suspension spheres or the hydropneumatic struts.

It appears that the only way to be sure is to replace them (the struts are £400 each), the subframe bushes are a very big job, the sphere is cheap and easy.

I changed the sphere (it made no difference).

It has been suggested that I swap the rear struts over. Apart from the costs of 2 litres of fluid, it is only a few hours labour. I may do that when the weather improves.

Interestingly, it has not got any worse over the years.

Good luck in finding your problem.

 

[Mickybo]

sounds like rear drop links for the rear ARB

 

[cd1974uk]

I have a knocking on the OSR of my W211 E320 CDI. The last 2 inches of the rear spring is broken off and rattling around in the wishbone cup very annoying.

I am waiting for the use of a telescoping spring compressor to change the spring, which should hopefully cure my issue.

This would presumably have been spotted on yours by now though?

Not the best pic I know

 

[dm250]

Hi all , thanks for all the reply's but everything has been checked on my car and they carn't find anything wrong with it !! I have said to them about the subframe bushes but as again they say they are ok , one of life mysteries I think , and how much money do I throw at it ? the car is 10 years old maybe time for a later w211 or a w212 , and my car is an estate not a saloon , how do the w212 compare to the w211 estate , thanks daren