Normally, a Benz rotor is thin enough (to save weight and improve handling) that turning it will take it below minimum thickness. Certainly attempting to turn a rotor after a couple of sets of brake pads will do it in. They are expected to be replaced every third pad set or so.

However, it is possible to get rotors with some irregular surface hardening from the factory grinding, giving you pulsating brakes as soon as they start to wear. This isn't limited to Benz by any means -- I've heard the same problem on a number of American cars. Don't know about Japanese. The cure in this case is a VERY light turning, just enough to remove a couple thousandths of an inch of material to remove the surface hard spots. Those spots wear more slowly than the rest of the rotor, leaving them high. NOT warped, just too much runout on one side.

If you have a distinct lip at the outer edge of the rotor, replace it. Rears are something like $20 on Fastlane, fronts are about $60 -- pretty cheap, and not that much more than it costs to get them turned.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!