I am sure this doesn't apply to all of your noises but FWIW I had a very similar rattle that sounded like a paint can rattle that happened at low rpm and only under slight load. I could not duplicate it by hitting the exhaust with my hand or by brake loading and all of the exhaust was intact. It turned out to be the rear cat tapping the protection plate on my Hanna sliders. Cut and turn of the cat and the noise has not re-appeared.
My 80 has a rattle near idle - then comes and goes (flairs) as the rpms increase - could be described as a chainsaw-like sound or rattle as in exhaust parts loosening up. It's embarrassing to drive in a parking garage or even on the street - the "flair" up resonates pretty loudly.
Mine has also developed this type of noise. It does not do it in Park, Neutral or when it is cold. It does do it when the engine has warmed up and is between 1000-1400 rpm, under a load and when backing off in this range. I would describe my noise as more of a clackety sound, maybe a rattle. I have nothing aftermarket on her. I have Pm'd the front axle and changed the T-case/front diff fluids to synthetic. Checked the AT fluid and it is full and pink. It has just started this within about the last 1000 miles. I have found no rocks, foriegn debris or loose parts in the front section of the truck. It has been mentioned to me that it might be the Torque Converter? The truck has 155k miles on her. Has anyone else checked anything I might have missed? Is this something normal? If it is, it sounds like crap.
Damn, I've been dealing with the same issue for three months now. Reading these piniging speculations have me a little spooked, what with the turbo and all... Think I may have to try the Seafoam out, I've always had good results.
Think I may have to try the Seafoam out, I've always had good results.