Can a OM 617.95x engine be flooded during repetitive unsuccessful starting attempts (e.g., prolonged cranking in conjunction with a defective glow plug relay)? If so, what would be the procedure for reversing the flooded condition?

YES! I have seen this. You will need to glow the system and have someone hold the stop lever down while you start the engine. IF it starts to crank, just let off of the lever and allow it to start.

I know this is an old thread but can some one go into a little more depth on the procedure for starting a flooded diesel. I spoke to a mechanic and he said my engine is probably flooded at this point. He mentioned squirting oil into the glow plug sockets. Also I don't know where the "stop lever" is.

You might try the diesel forum...

If you allready have too much fuel in an Engine why would you squirt Oil into the Glow Plug holes adding even more liquid to the cylinder?

Next if a Diesel was flooded wouldn't you have to remedy why the Engine did not start to begin with before you start cranking the Engine.

Next just letting the Engine sit will allow most of the fuel inside of the cylinders to drain down past the piston rings.

Also the pic below is of the STOP lever on a 617 engine; on other engines it may be in a different spot. Remember the paper with the words "STOP" may be gone.

If you "flood" a diesel engine you risk hydro-locking it.

I have been thinking on this. Depending on the volume of Fuel a small amout of Fuel would only raise the copression ratio as it would get pushed up into the Precombustion Chamber and simply compress the air more.

The problem would come when there is enough Fuel or Coolant in the Cylinder that it could not squeeze throught the little Precombustion Chamber holes fast enough or simply too much volume.

Hydraulic locking most often caused by a Coolant Leaking into the cylinder; mainly because of the volume of coolant avaliable.

With the type of Fuel Injection system Mercedes has you would really have to work hard to cause a Hydraluic Lock.
It would have to be something like a Broken Injector spring (no atomization and no fuel burning) and you would have to keep running the Engine inspite of the dead cylinder to fill it up with Fuel.
I suppose there would be a remote chance of poor compression doing the same.

The fuel would get blasted out of the cylinder on the exhaust stroke though, there would never be enough accumulated fuel in the cylinder to "flood" it....maybe cause a smokey rough start....but not prevent starting. I don't think its even possible to flood a diesel.