Any Pontiac guys on here? Need insight.

Yes, the main battery ground was very intermittent at best. He had been trying to figure it out so, there was all kinds of wiring unhooked and moved around when I got it. I just moved the ground to a better spot then, traced down wires and put them back in their proper places and we had power everywhere.

He had been turning over with a breaker bar about once a month and he had put a little oil in the cylinders at one point. I did not start it immediately. We cranked it over a bit with no ignition source hooked before it was started. To add a bit to this story as I talked with him yesterday, he told me that his wife heard the noise the day he pulled in the garage and, asked him what that noise was in which he replied I don't know, didn't hear anything. This just now came to him as he never heard it as, with the hood down and inside the car its faint. She heard that day and, I have a very short video of it so, she heard it again and it jogged her memory of hearing it that day. So, it did make this noise on its last ride but, I don't think it was doing it before that.
Only heard from the front of the car, not heard inside the cabin. Likely coming from the front of the engine…

The intermediate shaft is a red herring.

Just open the timing chain cover and inspect the timing chain and gears. Nothing to lose but a bit of labor and a couple of gaskets.

If it isn’t that, one less thing on the list of what it might be.

If it is that, problem solved.