01S8

this just started yesterday. i usually dont even look down at the temp gauge, but on the freeway i noticed it creeping toward the red line and the 'H'.
it seems to heat up right away and sit at the "normal" line on the gauge for a little bit, then start slowly getting too hot. now on every drive to work/home it sets off the warning light. but it hasnt actually gotten all the way to the right ... 'H' though.

The fans are both working properly, the coolant level is good, the radiator is hot, oil level good. this leads me to believe its the water pump...
tests i could do to determine what it is, and opinions please...

Acceler8

how many miles on your car?

PaulW

Okay, we've had a lot of other discussions about the fans this summer on the 32 valve motors.....

But with your description, I'll be you $100 it's the thermostat.

They fail on the 40 valve motors high and with exactly the same symptom as you have.

Get the timing belt done at the same time (and everything that goes with it). I have not done it on a 40 valve, but it's easier than a 32 valve.

pw

01S8

it has 54k on it.
now i just drove it, and it actually overheated. i had to park until it cooled down. and this time the radiator felt cold, except on the very end of the driverside, it felt hot.

what is all involved in changing the thermostat?
i havent gotten my repair cds yet.

PaulW

And as far as I can see, pretty similar to the 32 valve procedure, but you need different special tools, only three of them, less than $200.

You'll need to do this, or just have somebody else do it, make sure they have the tools!<ul><li><a href="http://www.audipages.com/Tech_Articles/enginemechanical/tbreplace0.html">Similar procedure, not as hard</a></li></ul>

01S8

from the pictures the thermostat housing is visible one the plastic covers and radiator hoses are removed. hopefully this isnt too hard to do.

there was also a clicking noise, like something turning on and off near the cowl when the hood was open. from the area where the auxiliary water circulation pump is located in the pictures at the link from audipages.

PaulW

The timing belt covers just clip on, and the belt/thermostat cover is a slightly different configuration, you need to remove the belt from my understanding to change the theremostat.

The clicking noise is most likely one of your HVAC dampers, but not sure. Or it could be your aux water circ pump, which runs all the time.

01S8

i cant believe they would design it like that. i mean seriously...

well i might do this myself, so where can i get those specialty tools? i dont suppose i can get them asap and do the job today/tomorrow?
the dealer has the parts in stock, and i have the weekend off.

PaulW

Otherwise you'll have to get them from a speciality tool place, there are two or three of them out there.

Here's the tools you'll need and an A6 4.2:

This one goes into the block and locks the crank shaft in place....

<img src="http://www.audipages.com/Tech_Articles/enginemechanical/40v1.JPG">

I don't know what this does, but the Bently would show it.

<img src="http://www.audipages.com/Tech_Articles/enginemechanical/40v2.JPG">

I don't even see the thermostat, but I know it's there....this is the cam locking device for the 40v motor.

<img src="http://www.audipages.com/Tech_Articles/enginemechanical/40v3.JPG">

<img src="http://www.audipages.com/Tech_Articles/enginemechanical/40v4.JPG"><ul><li><a href="http://www.zdmak.com/wbstore/main.asp?LowCt=0&amp;action=cat&amp;cat=AUDI%20TOO LS">Here's a place to get tools, I have bought from him before</a></li></ul>

SteveIAS8

is your car a CPO car?

Steve
'01 S8- 55k miles