Originally Posted by OM617YOTA

Thank you! My apologies, my first post was made while on break at work, and was necessarily brief.

This engine has been swapped into a 1990 Toyota pickup. Before purchasing the engine, I drove the '83 300SD donor car around the junk yard to verify all was well. No knock then, or obviously I'd have not purchased it. During the swap, it was necessary to remove the vacuum pump so that the engine would fit into the truck, and after the engine was resting securely on it's mounts, I reinstalled the vacuum pump. Got the engine started after some trials and now the vacuum pump is knocking. Removed the vacuum pump, started the engine and ran it without the vacuum pump, no knock. And a much smaller mess than I was expecting.

Timing device appears to have much less than the 1mm specified movement. There is what appears to my untrained eyes to be normal wear on the roller coaster track where the roller wheel would run on it, and likewise on the wheel, and no wear anywhere else.

Mostly I'm wondering what I boogered up while removing and reinstalling the vacuum pump. It did sit for several months between my purchase and being run again, could that cause one to go bad? I greased the rollercoaster track, ball, and bearings before reinstalling.

It's of the open-cage-bearing type, so I'll be replacing/rebuilding it regardless to protect my timing chain.

Thanks all. I looked for several hours on this site before I posted. I truly appreciate the help, and I'll post pics and video of the conversion when it's finished.