02-24-2013, 09:01 PM
Coolant flush on 2000 "S" at 12 years, about 50K mi. Daily driver with frequent oil changes since I bought it ( used 19K ). Ph was fine, no signs of contamination at that time, and the flush was more part of being proactive. The job is not hard, see the 101 projects book, or your Bently manual for the techniques involved in getting a good fill. Porsche antifreeze is EXPENSIVE and you want to make sure you use distiller (demonized) water to mix it. It's true that you will spend a bit of time getting the air bubbles out.