Quote Originally Posted by EagleMark View Post
I've never done an electric waterpump, but why would it take longer to warm up if thermastat was closed?
Because the coolant flows through engine, out the back of the manifold, through the heater core, through the radiator, and finally back to pump, until the thermostat opens. <50* outside and it takes forever to warm up while driving, due to the airflow through radiator, even without the fan on. I have contemplated moving the return from the heater core to the bottom of the radiator so the water returning spends less time in there but that requires rewelding fittings and making a new heater hose.