Isn't the lower hose supposed to stay cold? I don't remember which way our radiators flow, but I'm pretty sure it's top to bottom correct? The top hose should be hot because that's the coolant coming FROM the engine, whereas the lower hose carries coolant fresh from the cold radiator INTO the engine.

 

i did not know that thanks!!!

 

No problem.

Have you flushed the system out? You could have lots of junk built up in the system and a flush would help.

Also, you're an 00 which means you have a cabin filter. Have you changed that? I've seen some really nasty ones. Leaves and a bunch of random crap builds up on them and that could be another issue.

 

i recently put my engine in also had that same problem there was an air pocket at the highest point right under the TB.. i don't know if your having the same problem i couldn't find a bleed valve so i just unhooked the hose that goes to the EGR.. I let all the steam out until liquid flowed out... fixed my problem right up and heater started to blow hot again

Hope that will help you

 

from the egr valve? didi you do on a i4 or v6?

 

Maybe ur coolant temp sensor took a shit?

 

the sensor and the sender are both new