OK, my buddy with the 96 Park Avenue just got his car back from the shop today, needed a new upper intake manifold he said, the car didn't even sound like it was tuning over, just sounded like the flywheel or just the starter was spinning.
It cost him over $800, and he only paid $100 for the car
When he showed me the new intake manifold, the oil cap popped off, and there was this really strange stuff inside the oil cap. It was the color of dried up antifreeze
What could that be?

Antifreeze. Check the oil for foam and the radiator for oil. This is common with a LIM gasket failure.

Thanks, that is what I thought it was, but I thought the mechanic would have noticed that, since they changed the oil while it was there

Is there anything else this could be though?

It could be just a little moisture. If that'* the case try adding some seafoam to the oil, follow directions on car for this. Then change oil and filter.

OK, THanks
I recommended that to him before, since the car has so many miles (196K, and he said he would never buy a car with over 100K LQTM)
but he says he won't put any more money into the car
he is cheap with some things