If this was so, I would wonder why so many thermostats have a tiny bleed
hole. Not much point if they are never closed on any car.

Mark

Ben huot wrote:
>
> The thermostat is never completely close on any car or van, it is open or
> partially close (about 75 % close). Even if it looks completely close, it
> is not.
>
> On most cars if it was fully close the pump would have a hard time and the
> engine would overheat, even in winter condition.
>
> Regards, Ben