LR high pitch whine, 2000 ML430

[dakat]

Gilly,
I have a 00 Ml430 built in 04/00. I have this high pitch whine that comes from the LR fenderwell. When you first turn the key to postion 2 it sounds for 2 to 3 seconds, then quits. Sounds all the time with engine running. I know the fuel pump, filter, and regulator are in this location. I'm sure I don't have the latest upgraded parts installed. Although I have an appointment after the holiday I'd like your take on this as I'm sure you've had to deal with it in the past. I have 8 months left on my Starmark Warranty and I need to get rid of the noise and get upgraded if possible! Thanks!!