Mercedes-Benz W203 rear end rattle and creak
What causes a W203 rear end rattle in potholes?
The most common causes are loose lower or upper mounts and bushes of the rear shock absorber, the anti-roll bar's frame bushes and the front bushes of the rear subframe. A broken rear spring can also rattle, and it is not always visible, because the break is often in the lowest coil inside the control arm.
How is the cause of the rattle found?
Go through the shock absorber mountings and mounts, the anti-roll bar bushes and the springs. A shock absorber can be checked by lifting the car and shaking the wheel. One replaced bush does not always remove the noise, because there can be several causes. A broken anti-roll bar link and a worn wheel bearing can also tap.
Where does a W203 rear end creak come from?
Often the creak comes from the mount at the outer end of the rear lower control arm, which dries out and loosens. It can be tested by stepping on the rear door sill and listening. The mount is renewed, or as a temporary measure oil can be sprayed on it through the protective boot.
Does the rattling have to be fixed?
If the cause is a broken spring or a worn control arm joint, the part should be replaced. Have suspension work checked by a professional if you are not sure of the cause.