I have noticed recently that my car puffs some smoke everytime I start it and sometimes even after running errands. After dark this evening, the car's (behind me) headlights allowed me to notice that my car was smoking----puffing smoke at the redlight after making about an hour commute. This is my first diesel so I was wondering what could be the problem.
the car is a '91 300d with 79200 on the ODO.
it has been meticulously maintained (all scheduled service, and synthetic oil changes every 3000-3500 miles).

any thoughts and thanks for reading......