s-10 rattling noise.

[srtolly]

I once had a hamonic balancer make a very similar noise that went away with some revs. The rubber isolators degraded and fell apart.

[gxi]

This may not be applicable, but FYI forum-ers: My 1991 S10 Pickup 2.5L 5-speed had an intermittent rattle that seemed to be coming from under the drivers side floorboard. I was sure the tranny was doing something weird. Turned out to be a heat shield on the top of the front exhaust pipe, just below the manifold mounting. It only had little spot welds holding it on, and they'd broken. It was somewhat formed to the pipe, in a narrow space next to the bottom of the engine (which it was shielding, obviously), so it didn't fall off of its own. I pried it off with a ball joint separator. Rattle gone!