turbodiesel,

Given the abrupt change in oil consumption I would agree that while the rate may be within the range of what is considered "normal" it is not normal for your car.

I second psfred's assessment that the turbo bearings are shot. Like he said, anything other than smooth motion is a sign the bearings are no longer doing their job. If the rotating member is unstable as it spins, the likelihood that the seals have been damaged is high. I am not familiar with the internal lubricating oil plumbing and so I can't suggest how the oil is getting into your engine from the turbo bearing area. I would expect a quart in under 1,000 miles going through the intake and out the exhaust to be visually noticeable or at least as a change in exhaust odor.

That is about the consumption rate I had with my 1991 350SD after the engine rebuild that was diagnosed as a bad turbo bearing seal. Evidence of leaking oil was visually apparently in the inlet piping, which led to the diagnosis. The oil consumption was clearly going out the tailpipe - no mystery.

A refurbished turbocharger for that vehicle was close to $800 and not that readily available. Getting the old one out and the new one in looked like a real nightmare. Oddly, my 1998 E300 Turbodiesel turbocharger is much more accessible, althought the engine is more powerful and one would think the engine compartment of the car should be smaller and more cluttered, all of which would lead to the expectation that accessibility would be worse.

No leaks means you must be pumping oil out the tailpipe though.

Good luck, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)