Got the timing cover off the 2003 4.7 I pulled from my truck with 190,519 miles on it. I found the amount of chain wear surprising. Looks to me like the secondary tensioners are fully extended. The primary tensioner was also very extended but no photo because when I went to compress it with pliers like the service manual shows it snapped like a twig. Thought this might be interesting to the forum.

I bought the truck with about 48K miles on it and have run Mobil 1 oil the entire time I've owned it.

 

That's is interesting! At least to me it is

 

And I didn't notice until I posted those pictures but the right tensioner doesn't appear to be in contact with the arm.

 

Not surprised at all. The local dealer recommends changing the timing set out at 100k miles. Most people seem to wait till there slapping or untill major problems happen like timing jump. Overhead cam set ups arent good in my opinion. They work but arent as reliable without proper up keep.

 

Also surprising was the amount of wear on the tensioner arms. They were almost to the metal.