Sounds like lifters rattling from your description.  Very common with
vanagons when they sit.  If it doesn't go away, get worried then.  There are
times when mine might take a few minutes to stop rattling.
bmc  :)
"Faith will move mountains, but you'd better bring a shovel...."

> From: Fonni Chang <Fonni0365@CS.COM>
> Reply-To: Fonni0365@CS.COM
> Date: Thu, 5 Sep 2002 09:19:05 EDT
> To: vanagon@GERRY.VANAGON.COM
> Subject: New owner of 91 Westy -- sticky valve
>
> Hi everyone, I am a new happy owner of a 91 Westy, 92,350 mls, Auto trans. I
> enjoy very much being one of the Westy family, and enjoy reading and learning
> all these interesting posts. Yesterday evening for the first time, I heard a
> tapping noise coming from the engine compartment right after I started (she
> has been sitting in the garage for the past three days), I believe it was a
> sticky valve problem, because the noise went away after a short drive, then
> it returns to the normal smooth running. Anyone has any suggestion whether
> there is a good additive in the market for the Westy engine to fix this type
> of problem? Thanks
>