Is this chain tensioner failure???
 

OK, I think my pressure fed tensioner for the 4,5,6 bank failed. When I took the covers off the 1,2,3 chain was taut and the tensioner was extended. The 4,5,6 bank chain was tight on the bottom and loose on the top and the tensioner was already depressed adequately for me to place the pin in it with room to spare.

Thoughts??? I still have the old spring tensioners.

It sounds like it has gone south. If you could put the pin in it without having to compress the piston, it is totally crapped out, I have not seen one that bad, even the bad ones that won't stay pumped up, still have the internal spring holding tension that still had to be compressed to get the pin back in the hole. I just went through this repair myself, my right side on failed, but still had to be compressed with a c-clamp to put the pin back in it. Good luck.