John535is

I have done the CLR job, you won't find that one in the Audi mechanics guide book but it was the last ditch alternative before pulling half the car apart to get the heater core out. It worked, but its messy. What came out was like crusty grit. I assumed it was old coolant that had dried out from a past boil over before we purchased the car. The hardest part was actually trying to design a hose clamp arrangement so you can push the flush water through with some sort of pressure.

You can get a CV boot kit that is designed to use this plastic cone arrangement so you can expand the end enough to slip over the CV still attached to the shaft. (try fleabay etc) I have never done it, mainly because you want to clean out any dirt thats got into the grease. I used to race off road buggies, once you get dirt in the CV grease, it just grinds away in the CV until the cage collapses, not good. A CV boot kit comes with a little satchel of CV grease, all you need is some c clip pliers to remove the old CV, wash it out in your choice of degreaser, clean thoroughly and re-assemble with the new grease. Makes sure the grease gets right into and around the CV *****. From memory Audi use GKN cv's.

v_dubbin

I myself refused to believe this was a normal airlock issue. I went through a dealer flush, thermostat etc.

I finally got heat by squeezing the top radiator hose and the top heater hose while the engine is hot.

Just alternate one in each hand and squeeze one then the other about 10-15 times. it's kinda like you are milking the antifreeze through the hoses

I know this sounds totally ridiculous but do it everytime you lose heat and after a few days it will not happen anymore.

I went for days with ice cold air until I just started playing with hoses.

Your coolant level will start to go down a bit as the air bleeds out

v_dubbin

Oh one thing I forgot that also helps. Fill the coolant reservoir to the very top. Ignore the Max fill line. Fill right to the rim. I don't know what would possess the engineers to put the heater hoses so far above the reserve tank. It takes just a small air bubble to lock it.

Hope this helps others with this issue

lumpydo

I fixed it. Did the CLR trick. Let it sit for 10-15 minutes and rinsed it out, a few times. Just picked up a hose and let it run I to a bucket. And yes, there was a lot of garbage in there. I also reversed the 2 hoses on advice from an Audi tech. Now, it blows nice and hot. Thanks guys.