I don't want to harp on this, and really the two posters above have said it more eloquently than I can, but I still feel obliged to repeat what I said before. I would absolutely, seriously, NOT drive this vehicle until the problem was thoroughly investigated. If I were not going to fix it myself, I would have it flatbedded to a trusted independent MB tech TODAY (OK, Monday ....)

This is not an elective problem that you can live with a while until it declares itself more consistently. Also be aware that you are not just jeopardizing your own life but those of others on the road (can you say jaywalker?)

__________________
Steve
'93 400E