2006 E350 strange noise when turning
 

I have experienced an intermitent noise when coming to a stop and beginning to make a right turn. During the right turn it felt like a brake problem so I replaced all the brakes and rotors (45,000 miles and was needed) I also had the transmission mount replaced and put on new tires. While in for the other service I was told that my motor mount needs to be replaced eventually because i am experiencing a rough start first thing in the morning but at no other time and the car performs well. The right turn problem is still there and now it happened when performing a sharp left u-turn. That felt like my steering was going to give out which had me really freaked. When it happens the car is moving forward and not from a stop. Thanks for your thoughts.

Check Steering fluid
 

I've E420 and it was creating same noise. Then I added steering fluid and it calmed down at once