85 stock Westy, about 75,000 miles on original engine.

About a month ago, I started up one morning and heard what I think is
tappit noise.  I drove about 2 miles over to the local VW guy and he was
closed, but the noise had stopped anyway!  No further noise that I heard
until this morning, heard the same thing.  I'm about 80 miles from home and
had to get there, so I started out and stopped every few miles to listen.
'Bout 10 miles down the road, the noise had stopped and everything sounded
ok.  The oil has been changed more often than normal, the last time less
than 1500 miles ago and oil level is good.

Am I headded for trouble here?  Sticky pushrod?

TIA

Jim in Atlanta with sometimes tappin' Herbie, 85 Westy