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!