My 400E has the first version of the M119 engine in it. There was a change in the engine after a certain serial #. I don't know what was changed but the waterpump is different. I would think that if my car has been this trouble free and it is one of the firsts then they all should be good. Just check the harness, I got lucky on mine and it has been replaced, at least I think so. The '94, '95 models I prefer the most but the price jumps because they look newer.
1992 Mercedes-Benz 400E
2002 Mercedes-Benz ML500