look out for...?
Make sure the 0-60 time is somewhere between 13-15 sec., have a compression test done, a full pre purchase check by a Mercedes-Benz mechanic, and here's some checklists to look at when you look at a W126 and a diesel. The first link is for a W123 diesel, but some of the info is applicable to the W126 300SD.
http://mbdieseldiy.tripod.com/dog.htm
http://home.concepts.nl/~vlimmere/tips.htm
http://www.s-klasse-club.de/gb/kaufberatung.html


