I have a 2005 CDI with SBC that I pruchsed certified & used in 2006 from MD dealer. Does the 10 year SBC warranty start from 2005 or from when I purchased the car?

I hear a pump noise often & noticable more now than ever. No warneing lights or other issues

As I understand it, it will be the year 2005, NOT when you purchased the vehicle in 2006.

Based on your above statement, I would see the dealer rather sooner than later to get to the bottom of this and to hopefully still get this taken care of during the 10 year warranty.

Best of Luck!

The 10 year warranty is on the SBC pump not the entire SBC system. It starts from when the car was first registered. As you bought it used, it would be whenever the first buyer registered the car. So in theory a 2005 car could have been registered in 2004.

I have a 2003 W211 that I purchased second hand. The previous owner had the SBC pump replaced under warranty. does the replacement also enjoy a 10 Year warranty, or am I SOL if the pump fails?

The second one would just have the standard Mercedes warranty on their work which would be one year or 12k miles. So if it's been more than a year, you would be SOL if the pump fails. It might be years before that happens though.