Just back from another 1500 mi trip from Ft. Worth to El Paso to Riodosa
NM & back.
Left everything running fine, timing advanced as far as I dare, O2
sensor working.  But right from start there was noise like a loose fan
belt, only it only did it when warm.
Tightened fan belt but could not get it as tight as I wanted 'cause I
was out of bracket.  Changed fan belt. No help.  Seemed noise was coming
from water pump.  700+ mi. later, mechanic suggests I put detergent on
bearing.   It helped!
On return trip, stopped to chat in Roswell with a VW nut who sprayed
some lubricant (not wd40!) on it.  It worked!  Back in Ft worth, the
squeaking is back.
Question:  How serious is this?  I could keep spraying lube every few
hundred miles or so to keep it quiet, but I don't want a catastropic
failure.  I'm not losing water, water flow is good.  Ideas?

P.S. VW nut is hot to 'import' a Mexican bug.  He says it is easy to
register as a '68 Bug.  The only thing holding him back is money.  He
says he'll do the work if someone wants one.