ModestW12

This seems very similar to the issues I used to experience with my D3. I had to take it to the dealer several times. The dealer had to call in a regional Audi of America engineer and eventually I had to get an A8 advocate involved before the finally owned up to the issue and had the system replaced.

I have an Audi Technical Service Bulletin PDF which lists symptoms that match the issue you are describing though I can't recall if the final resolution to my problems involved the steps recommended by the TSB or more extensive component replacement.

Also, I have an Audi Engineering Self Study Program PDF that goes into great detail on among other things the climate control system. Pages 73 and 77 contain excellent diagrams that illustrate the components that may be causing the described symptoms.

I tried to attach them to this post and the uploads seemed to complete but failed (each attachment is ~4 MB so under the 8 MB PDF limit of this forum). PM me your email address and I can try to send them to you via email.
UPDATE: See my next post below for the attachments. I was able to reduce their size and the uploads worked.

mishar

Mine is doing the same but I think it is normal. Anyways it is 2005 so that doesn't count.

Edd W

I suppose we are living with 7 or 8 year old technology and car efficiency systems are moving at such a pace now it is hard to keep up.

Split cooling systems with separate flow to aid warm up, heated gearbox fluids from cylinder head coolant, alternators which act as motors to aid accleration, stop-start is back with avengance and heading our way for all cars soon, engine start from the alternator....it goes on.

Our cars are firmly in yesterday land and there is no way to make up for that - we just have to enjoy our cars as they are.

A8nightmare

Mine is an 05 and I get some warm air when I first turn it on. The blower comes on right away and that cannot be helped. The only way around the warm air is if the blower was controlled by a thermostat or thermistor on the evap coil so it would know not to turn on until the evap was cold.

Mister Bally

On my '04, I prevent this problem by turning the climate control system off before shutting off the engine. When I start the car back up, I wait a few seconds and turn the system on (auto). The problem is that it is not easy to remember to do this all of the time. Plus, it kinda defeats the purpose of an automatic system. Especially considering this is a luxury car.

pcamaj

so after looking at it more thoroughly, the air, comes only cool. the fan work, the blowers too. the middle vent is set to cool. thats where the air actually is a bit cooler the the side ones...

should he start by checking the freon ?

thanks fellas...

jakematic

This week I've noticed the air is a lot warmer than usual, mostly because it's hotter than hell and very humid.
My theory is that the front of the cabin and dash is getting extra sun load as well as high ambient heat from pavement and a hot motor.

When I ran back out for lunch after an hour drive this morning and 1/2 hour parked, it took a few minutes to really feel like it was cooling.

I reached back to feel the air coming out of the rear console vents - like a freezer!
Seems to support my theory, and FWIW my rear vents are the basic model not individually controlled.
Have learned to live with quirks of the comfort system as it generally seems to know what it's doing - and I get too impatient.

So have him check to see what the temp of the rear vents is.
Will help isolate to no cooling from low charge or some other issue.

ModestW12

Using Acrobat Pro, I compressed the technical service bulletin and removed the non AC system pages from the Audi technician self study guide. Not sure if you noticed my previous post in this thread but the symptoms you describe are exactly what I was experiencing before Audi replaced the failing components.

If your friend's A8 is CPO or is under extended warranty, you can use the TSB at the dealer to get the repairs covered. Otherwise, the TSB and SSP documents should be helpful if you and your friend try to tackle it yourself or take it to an indie.

mishar

I am sorry but all those thinks were used before. Alternator start was dynamo start (light motorcycles have it), most cars are cooling transmission fluid with engine coolant heating it when it is colder and alternator as acceleration helper is not really good idea. It should be huge to make any effect. Something like KERS system on Formula 1 may be, but savings will never pay back its price.

Edd W

I know, I had a Wheelhorse 12hp with a dynamo which acted as the starter as well.
Using the alternator to assist acceleration is part of a CO2 reduction package which means the current A8 4.2 fsi produces about 25% less CO2 while being about 7% more powerful than the D3 - as well as fuel economy improvements which are considerable - I think that is all pretty much worth the effort.