Check the timing chain for stretch -- I'm guess it is at least 8 degrees.

Typical symptoms -- excessive smoke, especially at high load and speed, lumpy idle, and injector knock, bad fuel milage.

Most are symptoms of late injection timing, but if the chain is worn, replacing it will fix both the late injection timing and the late cam timing at the same time.

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!