The coolant drain on the engine-block can be difficult to reach.

The plastic belly shield uses either a 8mm or 10mm socket/wrench to unscrew.

Be careful when tightening the radiator drain plug, if you tighten it too much the plastic screw will break.

I like to mix the coolant with distilled water.

I'm curious why the low level coolant light went on, on my W202 a faulty windshield level sensor could effect the coolant light.

Do a search for StarTuned Magazine and use the archive to read about coolant.

You might be on to something, if you meant windshield washer level sensor, because the car also tells me that the washer fluid is low.

Does any one know if draining the engine block coolant on this car is necessary and/or part of the standard coolant replacement prodedure?

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1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

I did a write up on my W202 but that is a '98. I think it is usually better to open the block drain. But I had to run water through the system for a while to get all the old coolant out anyway.

I am very curious about the colors you mention. I thought it was always straw yellow. Have they changed to green and orange?

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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 think I read that write-up a while back, just wasn't sure how much has changed from w202 to w203. Probably not much but you never know.

I asked the parts dept. guy at MB of San Diego about the green coolant. He said that the coolant used at the factory in germany is green and supposedly good for 100,000 miles. The orange stuff is the right/best stuff to use if you reside in N. America and need to replace coolant.

The factory green coolant isn't available in N. America. The coolant I purchased from the dealership is orange.

I would be more skeptical about the "factory green" coolant, except that the car was dealer owned and serviced prior to me taking ownership. I doubt they'd use non mfg. spec fluids.

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1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)