So....
for the past couple of days, pickle has been producing a very frustrating
noise.  It's a loud clicking sound, that, as far as we can tell, seems to be
coming from the engine compartment area.

When you hear it from the front, it sounds like it must be an interior part
rattling.  It doesn't click with any "rate", let alone a rate that
corresponds at all to engine or wheel speed.  This is why I rule out cv
joints (which are brand new, and have no loose bolts---I just checked) and
wheel bearings.  Sometimes it "rattles" *very* quickly, other times
intermittently.  But again, no direct relation to any mechanical speed in
the van.  There is, however, a correlation between the noise and
acceleration.

But then when you sit in the back and look for it, it seems like its not
coming from inside.  I've looked all over, removed all sorts of interior
items (and folded out the bed, etc), and it doesn't fix the noise.  And,
when you take the cushion out of the trunk, it sounds like the noise is
coming from the engine bay.

I also checked whether it could be exhaust headers hitting the engine
support bar, and it doesn't look like it.

Any suggestions as to what this could be?  It sounds kind of like a large
relay going on and off intermittently out of control.  In any case, other
than driving us nuts, it doesn't seem to have any impact on performance.

I've spent some time under the van looking over everything for "loose ends",
but to no avail.

Any help would be greatly appreciated!!!

-Wes