CJ7 No Heat after new heater core and blower

[Jeep CJ&7]

So my issue is that after rebuilding the lower airbox, replacing all cables, heater core and upgrading to blazer blower motor I'm blowing cold air.

Air blows great, and all controls direct air correctly. Heater hoses never get warm coming to/from the heater core. Hose to intake manifold is hot, the one coming from back side of intake to bottom of heater core is "warm". Hose going back to pump is cold.

Does this sound familiar to anyone? Worked fine before I did all the upgrade work.....

Blocked passage in intake manifold? Bad thermostat? (Stuck Closed) other ideas?

 

[mark sr]

What is the engine temp?
If the hose going to the heater core is cold once the engine has reached operating temps there must be some sort of restriction so I'd start by disconnecting/inspecting it.
If the thermostat was faulty you'd either over heat or the engine would take a long time to reach operating temp.

 

[TerryMason]

A bad thermostat would do it. I imagine that a bad water pump would as well.

 

[JPNinPA]

Can you blow air through the hoses and heater core?
If so maybe bleed the core by loosening the return line.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[ILOVESNOW]

Cooling system could be air locked.