I've been meaning to post an update but time isn't something I have a ton of these days.

It turned out to be the timing belt. The timing belt tensioner stopped turning, the friction caused the belt to heat up and start to melt to the tensioner wheel, and it seemed like the belt slid towards the head on the camshaft sprocket. When we got the cover off the belt was shredded near the head side of the sprocket. Replaced it, everything is good to go. Thanks for all the responses and advice, I appreciate everyone's willingness to help.