No, it isn't supposed to be making any noise.  Since the coil drivers are in
the ECU on your 2.1l Vanagon then I suspect that you have a bad connection in
there that is arching.  Sounds like you may need a rebuilt ECU before too
long.  I have them for $200, just give me a call.

Thanks,
Ken Wilford
John 3:16
www.vanagain.com
Phone: (856)-765-1583
Fax: (856)-327-2242