>>>The oil is leaking out of my Vanagon at a very fast rate, about a quart
every couple of days. Could this be a head gasket leak?<<<

No! Coolant will be lost from the head gasket, not oil.
Check the pushrod tubes for leak, head side and engine side, for that you
will have to remove the protective tin.
http://www.benplace.com/engine/engine_drain.jpg (you can see here the 4 pushrod)

Now, if you have an oil leak from the left side of the engine, am sure that
your have leak at the oil pressure sender, they are well known to be
defective, and that at a very fast rate.
http://www.benplace.com/oil_pressure_sender_overview_location2.htm

Here is some more info on that problem
http://www.benplace.com/oil_pressure_sender.htm

Regards, Ben
http://www.benplace.com
http://www.benplace.com/florida_trip1.htm