The whole time I've owned my van it's suffered from a loud, deep,
resonant sort of droning noise on the highway, from about 45 mph on up.
    (Well, okay, I'm the one who suffers.  I'm sure the van doesn't
care.)  I replaced the exhaust mounts and fixed all the exhaust leaks
without changing it one bit.

Well, today I got part of the intake snorkel, the upper part that goes
in the vent.  I don't have the rest of the pieces -- I don't even know
what other pieces there *are*, except for a section of paper tube
(though if someone with ETKA wants to let me know that'd be great) --
but I jury-rigged it with a length of 3" diameter aluminum flexible duct
from the hardware store.  I mashed the duct into an oval shape with my
hand so it would fit up into the vent area and mate with the air cleaner
and snorkel.

Man, what a difference!  It's easily half as loud at 55 mph as it was
before.  And I know some of the remaining noise is from the aluminum
duct buzzing against the bodywork, since I made no attempt to isolate
it.  I had no idea so much noise could come from an INTAKE.

Now I just need to come up with a permanent fix.

David Brodbeck, N8SRE
'82 Vanagon Westfalia Diesel
'94 Honda Civic Si