Seems the seals don't last forever.
These lasted 254,696 miles since the truck was built in 2006.
Here's the rest of the story and the photos.
http://www.tundratalk.net/forums/tu.../121338-32-valve-adjustments.html#post1030836
This would be the rail to injector seal if that fluid is indeed fuel. Of the rings between the injector and the manifold failed you'd have a vacuum leak (and o2 sensor "running lean" codes if it was bad enough), and the same vacuum would prevent fuel from actually leaking out.
<sarcasm>And only 256000 miles - what's the world coming to?</sarcasm>
