Merc E320 (Nov 2004) Turbo Diesel noise ??????

[EssexHSV]

Hi All
Sometimes when i unlock the car and before i even open the drivers door i hear a loud buzzing noise come from under the bonnet offside front area.
but it onlt make a noice for 2 or 3 seconds then stops and sometimes i dont hear it until i drive then it comes and goes. I can feel it throught the steering wheel aswell.
I have not got a clue what this is and i need to work out where its coming from.
Does anyone know what it is ???????
Thanks

[NeilyWheelie]

This happens on my 2003 e320 cdi. I believe its the sbc brake module pumping up or something...nothing to worry about iif yours has sbc brakes....but if it hasnt, i havent a clue, sorry!

[Aidayboy]

Mine does that too, wouldn't worry about it.

Have you also noticed the little mic's that drop down from the centre roof console, pretty cool.

[EssexHSV]

Thanks for your replies.
Whats SBC brakes ? lol The car with put its own brakes on if i use cruise control and im going down a hill.
I know sod all about Merc's and what they have and what they dont lol

[AC43]

EssexHSV said:

Thanks for your replies.
Whats SBC brakes ? lol The car with put its own brakes on if i use cruise control and im going down a hill.
I know sod all about Merc's and what they have and what they dont lol

SBC was an advanced (at the time) braking system which, if I understand it, is a sort of brake-by-wire set up.

It's pressurised and the noise you can gear is the compressor, know as the SBC pump.

It fires up at all sort of odd times and you can hear it/feel it.

Nothing to worry about. They all do that, sir.

If it fails, though, you'll get a warning light followed by a large bill.

Due to complexity and warranty costs, I believe, Merc ditched the system on facelift 211's

EDIT; here you go;
http://en.wikipedia.org/wiki/Sensotronic_Brake_Con...

Edited by AC43 on Saturday 21st June 08:13