SBC buzzing noise with no warning message-should I fix it or leave it alone?

[glasgow]

Hello, all... Just bought a 2005 W211, E280 CDI. Car has the annoying SBC buzz, when turn engine on and every 4/6 brakes.... I understand this is a common issue with SBC with lots of info in the archive. I asked the MB dealer who serviced the car and they said, they would charge me for a diagnostic test then will report to MB UK, but because the car is over 5 ys old they dobt if there will be any contribution from MB. I am inclined not to do any further action and just live with the noise. However, my concern is:

A) Is this SBC noise completely safe and is not indication of a higher chance of pump failure?

A) sometimes I also hear what sound like like fluid circulation in the bump, mainly at the morning start of the engine, is this also "normal"?

Thank you...

P.S.: One owner, 29K miles, Full MB service history till 2012 (21K miles), last service in sept 13 by merc specialist.

 

[Alps]

it buzzes, pretty normal.

I have heard really loud buzzing in some cars and its been fine.

 

[Satch]

Pumps do indeed vary but the SBC buzz of itself is not a cause for concern.

The fluid circulation noise you can hear is the auxiliary water circulation pump

 

[John]

If you get it when you turn the ignition on, it could be you are turning the car off during a charge cycle.

When you brake for the last time - just give the car a moment to go through a full cycle and then switch it off when done. You shouldn't really hear it when you next turn the ignition on.

Mine charges every three presses I think.

 

[glasgow]

When you brake for the last time - just give the car a moment to go through a full cycle and then switch it off when done. You shouldn't really hear it when you next turn the ignition on.

Mine charges every three presses I think.

Thank you and please excuse my ignorance, but I am not sure what is a charge cycle?

 

[mannikon]

http://www.mbclub.co.uk/forums/whee...nsion/87806-w211-sbs-pump-noise-solution.html

 

[John]

Thank you and please excuse my ignorance, but I am not sure what is a charge cycle?

The buzzing and vibration you feel through your foot every few brake presses.