On my 1987 190E 2.3, it makes a squealing noise when turning the steering wheel either left or right. Power steering fluid is at proper level. I checked the noise is not coming from the power steering pump and is isolated inside the car (steering wheel).

Any idea what this is or will this become a big $ problem?

I have the same problem on my 2001 E320.
Any ideas what could be wrong?

I have the same problem. When I turn the steering from the center position I hear a noise or groan through the first 15 degrees of movement with a turn to the right or left. This sound is not made with bumps allong the road. I believe this sound is not heard after 15 miles per hour. Any thoughts?

i remember hearing about a steering belt that could be frayed. ill try to look up more information on it. search here and on mbworld.org and benzworld.org for more info

__________________
Car which i own - 1987 Mercedes Benz 300e shown here http://www.cardomain.com/memberpage/790052

I have a 220 c with 100000 miles. This problem feels more mechanical.

I am not sure you are all describing the same problem. I can tell you that a "groan" is a classic symptom of low PS fluid. My C230 had the "groan" so I checked the PS level and it was technically OK. But I added a little more anyway and the groan went away. I also have a light "chirping" sound that occurs whenever I turn the wheel to the right while I am driving slowly. I really thought it was something in the steering wheel, but it turns out it is the heater fan that gets moved a certain way the the cars pulls to the right, causing the fan to "chirp".

Mike

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra