A squeak from the steering column is often related to a rubber boot in the column or a seal in the power steering rack.Google+
Car Problem Reports
Mercedes-Benz E430 Squeak in Steering Column Due to Rubber Boot or Seal
Mercedes-Benz E430 Problem
Average Mileage: 90,428 mi (60,000 mi - 152,000 mi)
Visitor, 2002 Mercedes-Benz E430, 152,000 mi
when turning the steering wheel in anyd directionI notice a squeak from the steering column. I put my ear to it and it sounds like its comming from the boot. Its sounds kike a material to material contact
Visitor, 2001 Mercedes-Benz E430, 60,000 mi
Rubbing noise when turning coming from steering column. Never has been fixed.
Visitor, 2001 Mercedes-Benz E430, 75,000 mi
Steering column squeaks when turning
Visitor, 1998 Mercedes-Benz E430, 85,000 mi
Squeaking noise when parking
Visitor, 2002 Mercedes-Benz E430, 100,000 mi
The squeak is more like a rubbing sound when you turn the steering wheel
rubbing scrubbing sound especially in during the winter months.