I'm still thinking it's the EGR getting activated on acceleration with side force (or following side force).

603's do not pool oil in the intake or turbo housing, and the smoke cloud was large enough to engulf a full sized car behind, this isn't a puff or two, more like a bad condtion MACK under full load!

It's possible that there is something floating around in the air filter housing, or possibly the air flow meter is broken (the later might cause the EGR to get switched on).

Peter

__________________
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!