Definitely sounds like the water pump.  There are good write-ups on this
online.  Might as well change your thermostat at the same time while you
have the housing out.  Also, you'll want to replace the little section
of hose coming off the thermostat housing.  I know Ken from Vanagain can
send you this, along with the gaskets for all of the metal coolant pipes
you'll be removing and the o-ring on the pipe that goes into the housing.

-Wes

Michael Elliott wrote:
> Jeez, if it's not one thing, it's another. There's this nice new sound
> coming from the engine, just about where the water pump is. A low-pitched
> grinding or growling sound that fades in and out. With the belt removed,
> the sound does not happen. Water pump pulley does not rotate real
> smoothly. Symptoms of a failing water pump? Fix quickee-quickee?
> --
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> KG6RCR
>