I've got a 98, 4.3L 4x4. Just had tranny rebuilt, and the infamous intake problem fixed. I noticed the radiator was kinda gunky, and the mech said it was still flowing fine, but flush it and keep an eye on things, so I did.
The problem: I loaned it to a buddy for a drive to the neighboring city for a job interview, and it died on the freeway and overheated. Having watched the temp gauge like a hawk and never got over 195-200 for 4 months, even on mountain trips, I felt it was okay. He said it worked fine until it just started to loose power and he pulled off. I towed it home, and let her cool down and fired it up. SCREECH, SQUEAL, RATTLE all at once. I figured water pump (sounded about that area). So I took out the shroud, fan and serpetine belt. All pulleys turn free and easy, and I started it back up with the belt off, smae noises....sounding like in the crankcase front. Did I spin a bearing? Is it the death rattle?
Oil is clean, and I flushed the coolant out to see if anything turns up in the water, before replacing the dexcool, and don't see anything(oil,shavings,etc) in there.
Thanks!! sorry for the wordy-ness.

 

So no accessories are turning and you still get the noise.. How did the oil pressure look? You can spin a rod bearing without affecting your oil pressure all that much, but not a main bearing...