Radiator and expansion tank
 

i just installed a Griffen radiator this past summer. Works great motor runs cool. But now in colder weather motor will not heat up all the way unless I’m sitting still. What I have noticed is the hose coming from the radiator to the expansion tank has coolant flowing into the tank at all times. Does anyone know why it does this and is it normal?

Yes it is normal. You should see a line for cold level and hot level. The expansion tank is just that, as the coolant expands when warm/hot it runs into the tank. When it cools off the coolant is drawn back into the system to always keep the level topped off.

i understand that, but it flows coolant all the time into the expansion tank, cold and hot. Is this normal?