esp noise on 4matic

[keith100]

Despite a lot of snow lately, the esp light has never lit up, even when the rear end steps out a bit. So, on some nice hard packed snow, I decided to hammer the throttle to invoke it. Well, the light came on OK, but I also got a fairly loud mechanical bang or two from underneath. Hope I haven't got a 2matic now!

Is this usual? I've never had a car with esp before and I'd assumed that the esp would just quietly put things right.

Any experience appreciated.

 

[jberks]

what year and model?
I had ETS rather than ESP on my 1995 C class. This was a forerunner of ESP and didn't cut the throttle or apply the front brakes, but simply applied the offending rear brake if it slipped. I got stuck on snow once and the banging noise it made was quite unnerving.
If you have full ESP I'm surprised you never see the light come on, mine sometimes triggers during gentle crusing - if I drive over a deep puddle for example. I rarely make a journey without the light coming on at least once..

 

[keith100]

Thanks for the reply

Sorry Its a 2008 c300. I have provoked it mildly over the past few weeks, with no apparent response from the dashlight just to see it in action. So this time I whacked it......bang. Sounded a bit like the ABS, but only one or two loud bangs, rather than the usual little chirps that the ABS makes.

The only thing I can surmise is that all four wheels were spinning and one suddenly found grip? Or maybe it suddenly threw all power to the front wheels? Didn't faze the car, which kept going fine, with only a small rear flick. Fazed the owner of those expensive mechanical bits though!!

Thanks

keith

 

[television]

Hi Kieth, the noise could have been just the drive cutting as it does when the car is provoked, it s just all of the splines suddenly being reversed when the engine power is cut, and it was under load when you did it

 

[keith100]

Thanks for the replies.

The car's still running and shifting smoothly, so I guess all is well and its just the way it is.

Cheers

 

[roofless]

i would think it's just axel bump or the subframe hitting

 

[keith100]

Good point, since there is in fact a TSB out for clonks from the rear subframe on the new C, or some part hitting it. I'll ask the dealer, maybe I need that mod.

Thanks again