ekufner

First of all Hello.
I am Canuck with an '02 S8 silver on black appx 80K miles and a long time lurker. I am just outside Bar Harbour Maine visiting family and due to return to Toronto Sun am, however what I thought to be an a/c issue is looking more like a thermostat given that coolant temps are rising to 120C. I tried to get a mech to fix but on the Fri of a long weekend good f****n luck.

I have Paul W's write-up for a the front end removal and his t-belt but having started his procedure it seems to be from a differently configured car. Is the thermostat at the front of the engine center upper just below that plastic levered arm thing (intake whatchamthingy)as per Paul W's timing belt write-up or is it in a different location. Is there a write up that I missed for a s8 thermostat? From what I have seen prior to purchase and since then there is a ton of experience on this forum and I would greatly appreciate and guidance.

Earl

ekufner

Hi,

Found a further post indicating that the thermostat is behild the t-belt cover and can be r&r'd by flexing the t-belt. I will continue removing the front end and at least take a look. Again any insight would be appreciated.

Thanks,
Earl

Mark'sA8L

I was able to do it without removing the belt at all. Used a lot of wire ties. A thermostat should not be a problem to get as it fits other Audi / VW models as well.

link below for when I did it

Also look in my picture poster on here of when I actually did my timing belt so you can see how the front of the 40v looks torn apart.

hope this helps in some way<ul><li><a href="https://forums.audiworld.com/a8/msgs/118335.phtml">https://forums.audiworld.com/a8/msgs/118335.phtml</a</li></ul>

ekufner

Thanks Mark...how do I get to your picture poster?? is the thermostat cover the long metal fixture that attaches to the lower rad hose?
Earl

gondar

You don't have to pull the front end on a 40V, A8CT is an expert on this and maybe I posted too. Search. My thermo stuck shut with no warning whatsoever at 90-some K miles.

You would have to pull the serp stuff, electric fan, mech fan and support etc, and perhaps de-tension the TB tensioner to get the thermo housing out. TB covers snap off. Repace the little vac hoses to the ex mani airdump valves while you are there. Use generic rubber vac hose.

Need a good 30 torx bit. Need 32mm(?) fan clutch wrench. Reverse thread hub.

Its not a casual job but under NO circumstances drive w/ a risk to overheat the aluminum engine. It not worth it. Use VW /Audi coolant.

ekufner

Thanks,

As a first timer decided to strip off the front end to give me a bit better view...i am just pulling off the housing. Will try first without removing the idler but see what happens. BTW just had to fix the kitty hose last week as was throwing a code...thanks

gondar

yes, that's it, unusually big housing

Phil3315

hope all goes well with the repair. Mine went at 155k on my '02 after being replaced at 100k when the timing belt was done. I really don't like these thermostats...

TonyA8

I believe they also sell fail safe thermostats. When they fail, they fail open so it will not lead to overheating, only over cooling. It will not damage the engine and will buy you time when it fails again. That is what I will be using when my 100k comes up to do it.

ekufner

Mark,

Success, 90C with the air cranked. Installing the thermo was a PITA but better than $1K and four days late for school and work. Thanks again for the advice, and to the others that posted in the past.

Earl