E46 330 heater help

[cheades]

I did a motor swap in my 330 back at the start of summer. Now as mornings are colder I found the car isn't getting hot water to the heater core. Worked before, I installed a new water pump/thermostat during the swap and the engine temp is fine. Tried flushing all hoses and heater core which were fine, installed a new heater valve as well.

Can anybody local maybe help diagnose the problem? At my wits end and about ready to just ditch the car.

[M3poseur]

Craig, just saw this. Did you figure it out? When you did the WP replacement. What brand is it? I have experienced the impeller was mounted backwards from the factory. Check that and report back.