1996 Chevy Silverado Low oil

Did the oil light ever come on? When running, do you hear any knocking or ticking?

The light never came on. Also, B4 the incident the oil pressure gauge was not working from a previous oil change. Since the incident, and after taking the truck to the same mechanic which knocked out the oil gauge to begin with, it now works again. I had mentioned to him the gauge stppped working after I had it in and his guys looked at it and couldn't fix it. Guess the gauge fixed itself accidentally.
When I first noticed the low oil accident, and for about 400 miles afterward, I heard a knocking and pinging internally below where the motor resides in the hood. Lately it has been better, but when I drive on gravel or bumpy roads I hear all sorts of rattleing internally below the motor. Lots of rattling. What could that be?? Are the parts so worn from driving at low oil I now have too much wiggle room internally. What would those parts be?? The check engine light comes on when I haul wood, but goes off when I get back into town and as of occationally, but latley I am feeling more secure in the fact I'm not going to break down in the woods. Knocking and pinging yes, what is pinging??? Thanks, brad.

Chances are when they changed the oil, they bumped the wire off the oil sending unit. As far as the noise on the gravel roads, that wouldn't be from the engine. Have someone check to see if there are any lose steering components in the front end. It could even be a broken stabalizer pin. As far as pinging, the valves will do it for one of three reasons. Cheap gas, engine too hot (preignition), or a bad knock sensor can cause the timing of ignition to change resulting in the valves actually making that noise.