I don't like the idea of stagnant coolant sitting in the heater core for
six months, so I leave the valve open year round. No one sitting in the
rear during the summer has commented on it being any warmer in the back
area.  This also makes it instantly available for those occasional chilly
nights.

I even open the front heater valve several times a month during the
non-heating season, usually about a quarter to a half mile before I reach
my destination.  This provides the additional benefit of cooling the engine
just prior to shutting it off.

        - Mark ** 91 Carat **

At 08:42 PM 11/2/98 -0800, Todd Last posted the following:
>Yes, and why would you want to turn it on and off?  On in the winter, off in
>the summer? Or is it just to aid in the installation of the core?
>
>Westys4evr@aol.com wrote:
>
>> The gray lever turns the coolant flow on and off thru the heater core.
>