Phil, Wayne:
In my continued quest to figure out reasons for tensioner binding, I've thought of something else....

The tensioners are actually an oil filter...traping fairly large particles...big enough to go down the feed line and not go past the piston/bore clearance.

Pieces of metal/etc. get pushed/caught at the bottom of the piston. When the piston gets pushed down by some event maybe this debris can grab the piston against the bore. I'll take some pictures and send but I see strange marks at the end of the piston and this may explain them.

-Henry