I believe this is fairly common.  At speed the ram intake of air from the
front creates quite a bit of pressure in the air box if you try to close all
the outlets.  This causes whistling and sometimes buzzing noises as the air
leaks past sealing flaps that are getting a little old and weak.

Larry A.

On Jan 25, 2008 9:53 PM, robert feller <syncro.carboncow@gmail.com> wrote:

> newer to me 86 syncro.
>
> when i have the defrost vent closed and the footwell vent closed I get
> some
> crazy "howling" through the vent doors somewhere inside the air box. Never
> had this on my 2WD Westy, so this is new to me.
>
> Is there some missing foam, cables not closing 100% or bent door in there?
>
> I may have the dash out this summer during a restore and replace of the
> blower motor. Anything I can do at that time?
>
> --
> Shawn Feller
> Ohio
> www.carboncow.com
>