Hi,
My pride and joy E230 Auto has only one problem. When I brake following a period of time on a straight road, the car seems to experience a thump like someone has bumped into my rear end. It seems to me as if the clutch orsomething isn't disengaging the drive on time.

Is this a common problem and can someone help me diagnose the problem.

Much obliged for any help.

 

Hi,
Is this when you brake or go onto overrun i.e. just engine braking. Tryt repeatedly applying power and then off in a rythmic pattern a few times.

If the later it is likely the diff mountings especially the diff nose.
If the former then I suspect a suspension bushing is shot or loose.

I assume you have nothing loose in the boot / under rear floor. e.g. Battery?

Mileage?
Vehicle history?
Might help locate problem.

 

Thanks that gives me something to discuss with my mechanic friend.

My car has 140,000 miles with a good service history and runs very well. I usually experience the problem when i've been on the motorway and come off an off ramp slowing to a stop with gentle braking. It can also happen in town when stopping at traffic lights.


I'm confident its not anything loose in the boot or bonnet.

 

I should have clarifies that it occurs when the car is almost ata complete stop.

 

Have a mechanic look at the drive shaft... my car has a clack noise just before to come at full stop..

 

maybe the differential?

 

My previous post stands but if the noise is in the centre of the car, just before coming to a stop and if it is a feint sort of clunk then this appears to be "normal" and a "feature" of the drivetrain. My 320 does it also. The original post suggested something much louder (....somebody bumped into the rear!!)
I do not actually know what makes this noise. I suspect that it is something in the gearbox.
I will find out since I am also interested unless of course somebody watching this thread already knows.
Stuart

 

Ju8st to clarify further, there is no actual noise that can be heard whilst driving. The thump is a physical lurch forward with no perceptible noise. The explanation that it could be a delay in the gearbox changing down from 2 to 1 seems plausible to me.

Thanks for the ongoing interest.