Strange exhaust behavior during winterizing

[Pmt133]

Both. When the thermostat opens that feeds the manifolds. The check ball T on the housing otherwise feeds the elbows with bypass water until it opens.

 

[Bondo]

Ok, I'll make sure I drain the liquid from the bottom of the manifolds to make sure. But I have a more basic (maybe stupid) question: Does the coolant come into the manifolds from bottom and goes up to the risers? Or does it come into the riser hoses (that I provided the picture above) and go down the manifolds?

Ayuh,..... Correct,.....