The pump is actuated by a roller that rides on an axial eccentric on the front of the fuel injection sprocket. The roller bearing can wear to a point where it eats up the shaft it is on and falls into the motor. If that happens, anything can happen. It might just go to the bottom of the pan without hurting anything on the way, but with something metal and about an inch and a half in diameter is rattling around inside the crankcase of an engine, all bets are off as to what the result will be.

If you heed the audible warning and replace the pump, all will be well. To replace it your best bet is a set of metric allens in 3/8 drive. On the 616/617 you will probably have to pull the power steering belt to ease the job, but it's pretty quick and easy.

Good luck,