And although off topic, I gave up on dusty, squeaky semi-metallics and switched to ceramics and life is good.

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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

I used to make large roller bearing races up to 26.5 inches in diameter.We had a problem one time after heat treating and final grinding the races grew .030".We started after that freezing the races in liquid nitrogen after heat treat,.
If you replace rotors again I would invest in cryro treated rotors.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

Get an IR thermometer so you check the rotor temps after driving.

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Prost!

If you don't want to pay for genuine MB rotors, which from my experience are not much more expensive than aftermarket brands, I recommend ATE coated rotors. The coating, as on the genuine MB rotors, is a light gray primer which protects the non-contact surfaces from rusting.

As mentioned a stuck caliper can cause overheating resulting in rotor warping. You may want to remove the front wheels and check that the calipers release completely, and that the caliper pistons move easily.

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Fred Hoelzle

Thanks everyone for the replies!

While I did not use a thermometer, both front wheels feel warm but not really hot.

The pistons in the caliper move in and out as they should and after jacking the car, they do not seem to be dragging.

All sets of pads (three sets now) have had nice even wear on all four.
set 1 was on car when we got it and looked almost new. Previouse owner may have sold car over this issue.
Set 2 I bought online. I may have put 1500 miles on them before I purchased set 3 from Mercedes.

The second warping was on a trip to chicago and I drove the entire trip. I know that my foot was nowhere near the brake pedal.

Please keep the thoughts and ideas coming!