All,

In all my years owning this car I have never felt what I experienced Monday
morning. The engine started up just fine, however it was shaking the entire
body of the car, and tons more noise than the clickty-clack that we all know
and love. Not only this the shaking was so violent that I threw the
serpentine belt (belt remained in tact). I drove it straight home 1/4 mile,
since it started getting hot quick. When I got home shut it down, let it
cool, it started back up, with lots more noise and shaking than I could
stomach. So back off until I can get some Ideas on further analysis as to
the possible root cause. I am hoping this is a manifestation of a one or
more bad injectors. I had just made the decision to get a replacement set of
rebuilt injectors to supplement my next oil change (the motor did not smooth
out as much with my last diesel purge treatment). What would this motor
experience if I had one or two injectors go bad?

Could this be a timing chain issue? Can not figure out what would have
caused the belt to jump. The motor was doing the herky jerky thing. A member
of another group feels that this may be the cause. He also suggested that
the vacuum pump may be the culprit, but I do not think the motor would have
shut off if this was the case. Maybe the guts of the pump are breaking
loose, the pump was replaced with new MB part 150,000 miles ago.  I am
afraid to start the motor until I can figure out how to better diagnose this
issue. If this does not sound like an injector issue, I am wondering how do
I diagnose other issue. Push rod, valve, lifter, timing chain, vacuum pump,
or worse.

What does everyone think? Has anyone experienced anything similar from this
motor?