Date:         Tue, 29 Aug 2000 04:18:17 PDT
Reply-To:     Mark Dorm <mark_hb@hotmail.com>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mark Dorm <mark_hb@hotmail.com>
Subject:      Re: idle before shut down [was wasserbox]
Content-Type: text/plain; format=flowed

And this minute to two minute idle before shutting down would apply to any
engine you might have in your Vanagon, not just the Wasserbox, because the
radiator is so far removed from the engine compartment.



>From: CHRIS STANN <cstann@home.com>
>
>I think the idle-down period is necessary after extended high-speed (75 MPH
>+) heats up the heads.  Higher revs = more frequent combustion = higher
>amount of heat energy to dissipate.  The coolant flows quickly and
>exchanges
>the heat efficiently, at the radiator end,  keeping your water temps down.
>When you shut down the engine immediately the engine experiences what's
>referred to as 'heat soak' -- the coolant over the heads is no longer
>circulating and it begins to expand rapidly as it approaches boiling.  This
>increases the pressure and pushes the coolant out into the overflow bottle
>which eventually overflows.
>
>You would not necessarily experience this condition in city driving because
>you head temps stay lower.  You water temps read higher because of lower
>engine revs, slower spinning water pump, and decreased air movement over
>the
>radiator.  So, lower coolant temps at the sensor do not necessarily mean
>lower head temps or lower oil temps.


> > > >The manual specifies that after hard running you must let the engine
>idle
> > > >for a minute before shutting down.
> >

_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

Share information about yourself, create your own public profile at
http://profiles.msn.com.