While I now have warm air coming from all the vents and realizing that I may have air getting into the system, I have notice that the bottom radiator hose is cold!
Is the bottom hose part of the pressurized system and should it be the same, or close, in temps as the top radiator hose?

 

Is your temperature gauge in the middle when the vehicle is warmed up , if not could be a bad thermostat. If the temperature is good you will probably have to flush the heater core. They get clogged with crud & do not allow good heat transfer,

 

Heater core is clean. I am sure its getting air in it from somewhere. The temp gauge is at mid scale after about 10 minutes and stays there

 

The lower radiator hose should not be cold- it may take longer to get hot but it should get warm/hot. Sounds like you may have air in the system? Did you bleed it with the heater core hose?

You may also want to try a new radiator cap as well...then drive around for a few and see if your heat increases....but it does sound like you have air in your system....

 

If the lower hose does not get warm/hot, do I still have air in the system?
I have bleed the system mostly from the heater hose and a few times from the hard pipe. I just think after 10 to 15 bleedings I am still getting air into the system.
At 2500 rpm and up, the temp of the air from the vents increases.
I don't think the cap is faulty but I will get a new one.
I am also getting a coolant flange. (just a feeling).
Any other ideas?

 

If your radiator cap is bad, the pressure isn't correct and it will impede the flow of the coolant...you can replace your coolant flange, but are you loosing any coolant at all? Do you notice your level in your reservoir going down?

 

It is going down only when it cools off which I think is normal. It increases when hot. Goes from MIN when cold to just below MAX when hot.
And I am not seeing any signs of a leak behind the engine or under the vehicle.
New cap tomorrow anyway.

 

Are you sure it is clean. 95% of the time I get a Audi in the shop the heater core is full of junk. Remove both hoses from heater core , flush with fresh water , blow water out with compressed air , fill with CLR , let the CLR sit overnight in the heater core , flush with fresh water in the morning , refill & bleed cooling system. Bet your heat gets warm.
https://www.google.com/#q=clr&tbm=sh...28848916038799

 

Should I take the heater core out and do this?
Last 2 times I flushed it out I left it in. I will need to get new clamps and gaskets / o-rings.
It looked like I am getting good flow through the core and very little scale came out.
I used straight CLR.
I did not let it soak overnight but ran a circulating pump on it for 3 hours.
Then reversed to pump flow and another 3 hours.
Over night I will let it soak.

 

I just flush with a garden hose both ways in the car , no need for removal. The hose clamps are reusable so no other parts are needed. Make sure the drain under the battery is clear or you will have a fish tank.