It was so loose it could have vibrated off, and fallen off no kidding.
I am so glad I noticed this! No positive seal at all.
I am not sure if the rubber seal shrank over the years or if a new seal & cap can be ordered..have not checked yet..anyways it was time for a roadside redneck fix...
I cut one paper gasket and then a thin piece of plastic to fit into cap below the real rubber seal.
I wonder if anyone else has ever discovered this problem?
I may call the dealer & see if a new seal & cap can be ordered tomorrow.
However this repair seems to do the trick !