GM 3.1L V6 ENGINE INTERMITTENLY STALLING WITH METALIC CLICKING NOISES & WILD RPM on 1995 Chevrolet Lumina

MY 1995 LUMINA-SEDAN 3.1l v6 engine at idling, recently starts to intermittenly stall with metalic clicking noise from the front of the engine around power steering pump, water pump or so. I have not been able to pinpoint it yet. The noise sounds almost like solenoid clicking, but louder. After the noise stops, the engine's RPM slightly moves up (like when the A/C compressor turn off). No error codes show up from OBD scanning. Also, this may be related: while driving at constant steady accelerator about 2000RPM, the engine RPM intermittenly surged and dropped, out of control. The water pump is about 8 month new, but the power steering pump has about 130K miles or more, of usage; and the engine is rebuilt with about 8 month of driving. Thank you for your assistance in advance!

by in Moorpark, CA on October 14, 2013
1 answer 3 comments
ANSWER by on October 14, 2013
Remove the drive belt, start engine, noise gone then? And is the check engine light on?
COMMENT by on October 14, 2013
I can remove the drive belt, no problem. However, the problem, metalic clicking noise & engine's stalling, occurs randomly and rarely at this stage; I had to idling the engine for a long period of times before it happened. I guess it is at the initial stage of the problem. No engine light is on. Can any guesses be made at this point? or a way to stir up the problem? Thank you for your replies for help on my old chevy!
COMMENT by on October 14, 2013
This is something that needs to be seen and heard by a trained tech./mechanic! This engine is known to have some rocker arm problems with high mile:age!
COMMENT by on October 14, 2013
The engine is a rebuilt one, with about 7k-8k milage! Also the clicking noise is not matching the engine RPM, I believe! Can it also be other issues? thank you!