flg8r90

On a 06 A8L : A friend of mine just got back from the mechanic and he told him he has a coolant leak. It is located where the entire front end of the car needs to be removed to replace. Can this be true ? I find it hard to believe that the same process to change out the timing belt is need to replace a couple of o-rings. He said he about due for a timing belt so it won't be so bad. I still find this hard to believe. The mechanic said it was typical repair and this happens in all A8's

Brozee

Need way more info. Miles?

flg8r90

101,000 . The mechanic also states that a timing belt should be replaced at 105K miles not the 75K that is specified from Audi. But I have heard a lot of mechanics say the same thing.

Brozee

You can change it whenever you want. I would do 100k depending on how many years old it is. Your friend needs to have the timing belt done.

flg8r90

So the coolant leak and the o-ring repair with the labor is typical ?

DA8

There is nothing suspicious about that. The thermostat is in the water pump housing buried where the timing belt is. You need to pull off the front end of the car to access it. If his leak is coming from the water pump/thermostat, then yes the mechanic is absolutely correct.

DA8

Here are some images to illustrate. Notice how the thermostat/waterpump housing is located underneath the timing belt right in the center where the two sides of the timing belt V come together. And notice how you have to remove the whole front end to access the timing belt to change it out.

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Vicl

I remember replacing thermostat myself on Audi V8, 1991, 3.6 PT. essentially it is the same engine as modern V8. To be honest I’ve done it without front disassembling. Yes, it was tight on space and it was difficult to remove it. But it could be done. I remember it took about 1.5 -2 hours to pull the old one and install the new one. And of cause it required the coolant flush.
I had a problem to let air out of the system. It was a bit of pain. The only method that worked for me to drive the front to the ramp and keep steady revs about 3000. That the only thing what helped me fully let air out of the system.
New A8 is much more complex with way too many additional small pipes and etc.
Good luck!

jandreas

I thought the double o-ring was located on the other side of the engine? and not below (and behind the camshaft gear) the thermostat housing?

05SilverA8

It is possible to replace thermostat without removing nose clip. I have heard that is it not fun but can be done. If timing belt has not been done, this is a good time to do that.