Dave,

may I add to that list:

-poor seal between manifold and head (check for soot marks)
-muffler on way out
-torn muffle mounts (not readily visible, take them off for good look)

Alistair

on 23/2/03 7:57 pm, David Brodbeck wrote:

> I can also add that droning, resonant vibrations *can* happen on a diesel
> Vanagon.  Mine has one at 55-60 mph...I don't have a tach so I'm not sure
> what that works out to RPM-wise. I very much doubt they did that from the
> factory, so I suspect mine is caused by one or more of the following
> problems I've noticed on my van, which I'll be correcting in the spring:
>
> - Missing air intake snorkel
> - Torn left-hand rubber exhaust mount
> - Small exhaust leak at entrance to muffler
>
> Generally worn-out engine mounts are also a possibility.  Mine is an '82
> so it has the rubber bushings on the carrier bars.  I haven't ridden in a
> Tiico so I don't know if I"m hearing the same thing, but the engine noise
> seems twice as loud at 55 as it does at 50.  It seems all out of
> proportion to the change in RPM between those speeds.