Okay, I had my 04 A8 for 2 years now. It over heated 3 times and everytime the dealer says its the thermostat. Princton Audi replaced twice and it overheated 2 weeks after they replaced it the first time. Now 15k miles later it overheats again. Since it did it while I was at a friends house they towed it to Willow Grove Audi. I asked the SA how much would it cost if I didnt have the warranty and he tells me its 1,000. That is a ridiculous price for something that faulty like that. My CPO warranty is up around March of next year. Trying to figure what should I do now... The car have 79k miles on it now.

Wow, I have 92K on my '04 and I have never replaced the thermostat. I consider my self lucky. Try replacing front adaptive shocks and then see how much you have left in your wallet ~ $5,000.

Lucky for me it was covered under CPO.

Mine was replaced around 40K miles...3 times though...that is crazy...has to be another issue or their just cleaning the damb thing and reinstalling it...its a mechanical part-spring activated...I would call Audi Of America or take it to a different shop/dealer...on my former '94 Toyota 4Runner one mechanic actually flushed the system and it cleaned the thermostat as well for a little while longer and quick fix but then had to replace it along with a head gasket a few months later!!...maybe the same issue here?? There's quite a bit of labor involved on the A8's...funny how these Audi mechanics are not really certified to work on A8's...it's a trial and error thing with them...at least at Braman Audi here in West Palm. They rely on the vag software/car's computer to pinpoint the issue or else they are clueless!!

It’s not a thermostat. You should clean your radiator first. The excessive heat damages the thermostat. I had the same problem. Here is what I did to fix issue with overheating:
1. drain the existing fluid
2. use 300 gram of Citric acid and distilled water to refill the system instead of the cooler fluid
3. Started my car, turned on the heat to MAX (this step will heat the small radiator as well)
4. Then I had to drive on it to do few things
5. in about of 1 hour of driving I came back and drained the system. You should see how much garbage came out.
6. refilled with HOT water, started it again and drained again. I did it about 5-10 times before the water became clean
7. Then took original Audi fluid, mixed with distilled water and refilled

At first I had a problem to push out all air from the system as I do not know the proper process for that exercise. But after I did it I never had a case when I was close to overheating (always normal temperature for 8 years now).

It’s not a thermostat. You should clean your radiator first. The excessive heat damages the thermostat. I had the same problem. Here is what I did to fix issue with overheating:
1. drain the existing fluid
2. use 300 gram of Citric acid and distilled water to refill the system instead of the cooler fluid
3. Started my car, turned on the heat to MAX (this step will heat the small radiator as well)
4. Then I had to drive on it to do few things
5. in about of 1 hour of driving I came back and drained the system. You should see how much garbage came out.
6. refilled with HOT water, started it again and drained again. I did it about 5-10 times before the water became clean
7. Then took original Audi fluid, mixed with distilled water and refilled

At first I had a problem to push out all air from the system as I do not know the proper process for that exercise. But after I did it I never had a case when I was close to overheating (always normal temperature for 8 years now).

You would think changing the fluid would be part of the solution?? Once again dealers cutting costs and corners hoping to rape us out of warranty!! I think I will look into getting a radiator flush done as well just as a precauion...I don't see it on my work order as being performed?? THANKS VICL..

Thanks for the ideas. I will get the radiator flushed when I get the car back Thursday. I never thought it would be that. I will flush it a few times like you did. I hope this works. It sucks to be out with friends and the car overheats.

Yeah, my thermostat went bad at 38k on my 07.

Yeah, my thermostat went bad at 38k on my 07.

'O7?? I though this was an '04-'05 issue?? Will definately flush it now...X2 with the overheating/friends or even family...really sucks to have to put the heat on when it's 90 degrees out to keep the engine cool!!

I'll only say that EVERY time I ever flushed a cooling system on the many, Audi's and VW's I've owned; within a month the water pump starts to leak. Lesson learned.

And yes, I always used the proper coolant.

I'll only say that EVERY time I ever flushed a cooling system on the many, Audi's and VW's I've owned; within a month the water pump starts to leak. Lesson learned.

And yes, I always used the proper coolant.

That is nonsense.
In Europe Audi recommends to flush G011000 fluid on all V8 engines every 2 years or 60000 km/ 37000 miles. The reason is due to the excessive heat that impacts coolant lubrication abilities. As a result it puts more stress on pump. If you flush the G011000 every 2 years the pump will never leak or will need to be replaced.

NEVER replace G011000 to G012000. Those are very different animals. If you do it the leak is guaranteed!!!!

G012000 is much "stronger". Audi recommends to flush it on V8 engines every 5 years or 150000 km/ 90000 miles fro the same reasons. You’ll save your pump.

With best regards,
Victor

You would think changing the fluid would be part of the solution?? Once again dealers cutting costs and corners hoping to rape us out of warranty!! I think I will look into getting a radiator flush done as well just as a precauion...I don't see it on my work order as being performed?? THANKS VICL..

I do not think changing the fluid will solve the issue.

Take a look at any water heaters. The heating element is covered by build up that is essentially minerals from the water. Take a look at your water boiler in your house (I’m sure you use one for tea and etc). To clean that build up you can use the vinegar or citric acid. A half glass of vinegar and few litres \ a gallon of water when you’ll boil it will clean that build up. The boiler will looks like NEW inside.

But do not use vinegar for aluminum. The vinegar is very active acid. It will “eat” aluminum as well. For that reason I do that exercise with Citric Acid. It’s very mild and it is safer then any commercial cleaners. In addition to that it is GREAN. It is absolutely natural product that everyone eats as additives in almost all products.

To make the long story short, if you’ll just flush it without proper cleaning the radiator from inside you’ll definitely be better, but not much. By doing it right one time you’ll forger about any issues with overheating for many years ahead.
Obviously it’s your choice.

That is nonsense.
In Europe Audi recommends to flush G011000 fluid on all V8 engines every 2 years or 60000 km/ 37000 miles. The reason is due to the excessive heat that impacts coolant lubrication abilities. As a result it puts more stress on pump. If you flush the G011000 every 2 years the pump will never leak or will need to be replaced.

NEVER replace G011000 to G012000. Those are very different animals. If you do it the leak is guaranteed!!!!

G012000 is much "stronger". Audi recommends to flush it on V8 engines every 5 years or 150000 km/ 90000 miles fro the same reasons. You’ll save your pump.

With best regards,
Victor

How can we tell the difference? I have an '04 A8L...I went through my maintenance manual and see nothing about replacing coolant...it just says check coolant and add if necessary?? It goes up to 95,000 miles (145,000 km)...am I to assume I have the 150K km G012000 fluid??

How can we tell the difference? I have an '04 A8L...I went through my maintenance manual and see nothing about replacing coolant...it just says check coolant and add if necessary?? It goes up to 95,000 miles (145,000 km)...am I to assume I have the 150K km G012000 fluid??

G012000 is red one. My new A8 has G012000.
G011000 used on older models. I have G011000 on my old V8 and I keep it that way and changing every 2 years. No issues at all (always cool and no leaks).
The colour of G011000 is dark green.

In addition to that the expansion cooler tank has a sticker with type of fluid used on that particular car. By comparing the color and the sticker you can tell if there is something wrong with the fluid or not.

G012000 is always suppose to be clean and sort of transparent, G011000 dark and true green. If you’ll notice any other shades of colours in G011000 then it is indication of problem (oil leak, rust and etc changes the colour of G011000).

I hope I answered your question.

North American market simplifies everything.
Here is what is required to do in Europe every 2/5 years:
1. Flush the G011000 fluid on every V8 engine, some other engines require the same interval, most have 5 years cycle
2. Flush the brake fluid. Audi uses DOT-4. It is extremely quickly absorb the moister from the air. As a result it boiling point is dropping from DOT-4 specifications
3. Air filter
4. Every 5 years flush G012000 fluid on every V8 engine

My car has the red/pink fluid and the label says G12...Here's some additional info I found online:
Audi models manufactured before 1997 used blue coolant. The Audi part number is G011000.Audi models manufactured in 1997-on use this red or pink coolant. The part numbers are G012A8D and ZVw 237 G12.Audi models began using this purple coolant in 2003. The different part numbers are G 012 A8FM, G 012 A8F A1, or G 012 A8F A4. This Audi coolant has recently been introduced as a replacement (and is the same as) for the earlier red or pink G 012A8D Audi coolant. The purple and above pink Audi coolant are interchangeable and can be mixed. This is the updated G12+ Audi coolant.

How To Change Engine Coolant On An Audi V8:

When the engine has cooled down, remove the Audi coolant tank cap.
Draining the Audi coolant from the V8 cooling system:
There are 2 drain plugs. One on the drivers side and one on the passenger side of the oil pan. To drain the Audi coolant from the radiator, remove the lower passenger side radiator hose.
After the system is done draining, put the Audi coolant tank cap back on. Carefully work off and remove the smallest hose that is connected to the top of the Audi coolant tank. Be careful, the tank nipple likes to crack and break off.
With a blow gun and compressed air on low, carefully insert the blow nozzle into the small hose. Wearing safety goggles, carefully force the air out so that any Audi coolant that's still trapped in the cooling system is released.
Reinstall the Audi coolant drain plugs. Reinstall the coolant tank hose(s). Fill the Audi cooling system with distilled water. Start the car and air bleed the cooling system as outlined in the factory Bentley manual. Run the car until the cooling fan comes on.
Repeat steps 1 through 5 until the water comes out clean.
Verify that you have the correct anti-phosphate anti-amine G11 or G12 Audi coolant. If it's full concentrate, mix a 50/50 ratio per the Bentley manual. Fill your Audi cooling system with this 50/50 mixture. Note: Some factory Audi coolants sold by dealers are already premixed and do not require further delusion.
Run the V8 engine and check for any Audi coolant leaks.
Top off the coolant tank to the fill line. Do not overfill.
Using a permanent marker, write 'G11 or G12 coolant Only' on the Audi coolant tank.
Be environmentally responsible and dispose of your old Audi coolant properly.

Can anyone with a Bently Manual give us this info:
Start the car and air bleed the cooling system as outlined in the factory Bentley manual.

'O7?? I though this was an '04-'05 issue?? Will definately flush it now...X2 with the overheating/friends or even family...really sucks to have to put the heat on when it's 90 degrees out to keep the engine cool!!

Not to worry, davie is a rare bird as far as 2007 A8/A8L/S8 owners are concerned. That is why Consumer Reports solidly recommends the A8/A8L/S8 from 2006 on. Average or better than average reliability (again, 2006+ only) and class leading safety for all model years makes CR recommending the 2006+ A8/A8L/S8 ultra easy. You dig?

Not to worry, davie is a rare bird as far as 2007 A8/A8L/S8 owners are concerned. That is why Consumer Reports solidly recommends the A8/A8L/S8 from 2006 on. Average or better than average reliability (again, 2006+ only) and class leading safety for all model years makes CR recommending the 2006+ A8/A8L/S8 ultra easy. You dig?

Honestly I am not a believer of any Consumer Reports...I do my own research online and on forums like this..IMHO comparing a '06+ to an '04/'05 is a bit crazy due to the price difference/wear&tear/redesigned look. '04/'05 are older models granted and will require a bit more maintenace because of wear & tear and lets not forget when these cars first came out in late '03 many mechanics had no clue about them at that time and some still don't...2-3 yrs later combining the hands on experience and a better diagnostic software makes life better... if maintained properly (like mine)..I would not say it is less reliable..older car which will probably require more maintenace..OK..I would not trade my '04 for any of the current similar model A8(L) - the full front grill doesn't sell me for some reason...maybe an S8 or W12 for the performance upgrade??? one simple thing I still meet up with is how many tire shops don't put the car in jack mode...IMHO overlooking simple things like this can lead to some issues down the road.

Honestly I am not a believer of any Consumer Reports...I do my own research online and on forums like this..IMHO comparing a '06+ to an '04/'05 is a bit crazy due to the price difference/wear&tear/redesigned look. '04/'05 are older models granted and will require a bit more maintenace because of wear & tear and lets not forget when these cars first came out in late '03 many mechanics had no clue about them at that time and some still don't...2-3 yrs later combining the hands on experience and a better diagnostic software makes life better... if maintained properly (like mine)..I would not say it is less reliable..older car which will probably require more maintenace..OK..I would not trade my '04 for any of the current similar model A8(L) - the full front grill doesn't sell me for some reason...maybe an S8 or W12 for the performance upgrade??? one simple thing I still meet up with is how many tire shops don't put the car in jack mode...IMHO overlooking simple things like this can lead to some issues down the road.


I agree with you're entir post. Especially the CONsumer Reports distrust. I got sick and tired of their bull$hit almost ten years ago trying to ramrod their "green stance" to every reader and subscriber. I stopped subscribing after almost twenty years of subscribing. I was never fond of their CONstant "no reCOmmeNdation" for new GM vehicles yet amazingly, they would sometimes recommend new Honda and Toyota models because they CONsidered them close "disciples" of previous models so CR felt theyt would be just as reliable. Screw them. FYI, I bought my wife a 2005 GMC Envoy new in December, 2004 and finally, the first problem surfaced a couple of months ago: a failed fuel gauge (fuel used computer still works) after 76,000 miles aand almost 5 years. There were 0 (zero) factory defects with that car. I only took it back to the dealer once, for a free oil change and then I've done all of the PM myself.

CR is highly overrated these days. At least on the automotive front, IMO.