When i step on the throttle at low speed, my engine makes a noise almost like a small chain being drug on concrete. Im not much of a mechanic but i can fix minor problems just fine. was just wonderin if anyone had a similar problem so i can figure out where to start. My truck is a 01 Z71 1500 5.3L

 

I have heard the same noise myself. Its pretty faint but I have a feeling its an octane issue . try octane boost then see if you hear it. I just put a bottle in the tank today. Ill keep you posted.