I have a Mercedes that has rattle at the rear, the rattle only happens when coasting, as soon as the power is on it stops. Its difficult to explain but at very very slow speeds its a creak, but as the speed increases to say 25mph and above its a rattle, only heard when hitting bumps in the road and coasting.

 

I have tried driving with the boot popped, the roof slightly open, the boot stripped, someone else in the car feeling around for loose trim and nothing.

 

Interestingly though, If its rained and the road is wet the creak/rattle isnt there, so I am guessing it might be something underneath the car, are there any components/bushes that are known to rattle/creak, and 'quieten down' when wet??

 

Thanks, Dan

Is it a c class? If it is, it would most likely be shockabsorbers

Is it a c class? If it is, it would most likely be shockabsorbers

 

It's an SL class with abc shocks..

It will be more than likely to be connected to the abc shocks as they go wrong quite a lot, also not cheap to sort out

It will be more than likely to be connected to the abc shocks as they go wrong quite a lot, also not cheap to sort out

 

That's what's worries me. I have never had a bush/suspension problem before that causes a rattle, normally a knock. What's strange to me though is it comes and goes with the rain..

Are you sure the noise goes away on a wet road, or is it possible the rattle can't be heard over the water spray, because I tend to find my cars have all seemed quieter in the rain or on very wet roads, but its probably just the water spray cancelling out other noises as it were.

To test this, on a nice dry day drench the rear suspension with the hose pipe and then take it for a drive, the roads will be dry and will test this theory.

If the noise disappears then it sounds like a bush type problem as the water quietens them down, but personally my 1st thoughts were the shocks, sounds like they've got some play, but under power/load the play is taken up with the weight transfer and the noise disappears.

Otherwise have a good look at the springs, I've known people drive around with a broken spring complaining of creaks and rattles.

Probably talking *****cks though!