Oh, sorry, I see it's a AEB turbo engine now.
i think that the coolant must have to get up to 90°C so the thermostat opens & let's coolant thru the whole system, once it can do that it will push any air bubbles locked up inside, out & around so they float to the highest points.

So far I have never seen a 1.8 Turbo engine bay up close. Just my APS 2.4 V6, & ADR 1.8 & APT 1.8 (electric throttle version of ADR, with other differences)

I found this on the net. https://www.audizine.com/forum/showthread.php/296647-Bleeding-air-from-the-coolant-system-air-bubble-in-the-coolant-system
It's got a good link to a download about the engine cooling system.
And there's a fair amount of info on YouTube. YouTube's quite handy really. Search it for info about the heater box & you will see the motorised metal flaps inside it, with the 3 holes in it (dash centre+ side vents flap) & no foam covering it at all. It's not mentioned in the video.
Once I do that job again on another car I will detail it with photos of every step. Im quite confident about doing it again.

 

Hm, cant find it ? :P

 

I don't get the point of that /\. Unless it's meant as a joke, like disconnecting the AC compressor plug will stop it from working & that's all, leading on.... It's going to get hot in the car without a working AC unit.. I think that's the joke...

​​​​​​But,
1. Is there bits of foam comming out the interior vents?
2. Is both of the heater core hoses hot when the engines hot?
If yes to both, then it's a heater box flap/foam problem.

 

No foam from vent. and both hoses are hot.

I changed the Coolant Temperature Sensor and the Coolant Flange. The change went well and i filled up with coolant and started again.
It took about 5-10 mins and it was up to 90C, but no hot air.
Opened the matrix hose and bled the system. Sill no heat, i think its more air inside.

And upper/lower radiator hoses are about 35C.

After a while the gauge was about 110C, but 85 with a lasertemp at the tempsensor hose ?!

 

I had basically no heat and replaced the thermostat and I think it fixed it somewhat (didn't have a real cold evening to test it).

I might be mistaken but I understood in the AEB if the thermostat failed, it failed in the open position? < which would lead to cooler water going around on a cold night, impinging the heater if required.

Also is the shitload of foam that I got out of my air vents now meaning that the appropriate air (hot or cold) can't mix properly?

 

Well, i have a brand new thermostat installed (not tested in hot water). But the chances its broken is small.

 

I used a small pump hooked directly to the heater core pipes. When I 1st turned it on a huge chunk of black $h!t came out. I left it run for about an hour. Started with CLR/ Water/ ethylene glycol mix (Prestone green) When it was done it was nasty diarrhea brown. Has been good since the (2.8 liter 30 valve V6)

 

Why is there always some douchebag like you ^^ that tries to represent themselves as an authority on everything they're not?

The "Climate Control" (believe it or not) controls the climate.
If the Climate control module is not working properly, it can fail to turn off the A/C compressor, causing it to blend cold air with hot, which is why (basically) everyone who has this problem experiences "luke warm" air. That's because you're taking extremely cold air and mixing it with extremely hot air = medium. Just like taking two pots of water and pouring hot into cold....it turns warm.

The guy that owned my car before me spent thousands of dollars trying to get this same exact problem fixed (at Audi and an Audi specialist). None of them were ever able to figure it out. I did.

I was having the same problem - and being an Engineer - I considered every component involved. I got under the car to see that the A/C compressor was running (which it definitely should NOT be at "MAX HOT". By unplugging the Green and Purple clip, you are manually killing the signal to the compressor and you will hear the compressor disengage immediately.....and by the time you make it back to the interior of your car, it'll most likely be too hot for you.

I have proven this, so please keep your ignorant arrogance to yourself, unless you can prove what you're talking about, or disprove what someone else is talking about, super cool guy. Make sure you're at the counter when I'm ready to check out at the parts store. BTW: Killer wing dude!

******* Douchebag.Hurting people you're supposed to be helping, with your bullshit opinions. The least you could do is use proper grammar when you're running your dick sucker and pretending to know **** about B5s.

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