Rdizzy

Hello all,


I am a newbie and needed a little help. I find a lot of useful information on this site and value the knowledge of the posters on this site.

Can anyone tell me the location of the thermostat housing on my 1997 A8 Quuattro 4.2?


Thanks Rdizzy

silverd2

You really don't want to know
On the front of the engine, upper left side (passengers) next to the water pump. Requires timing belt removal to get to it. Very involved, including front end of car removal (most do), fans, serpentine belt, etc..

http://www.audipages.com/Tech_Articl...eplacement.pdf

http://www.freewebs.com/ltooz/98audia8.htm#394830226

A few very talented mechanics have gotten to it without total t-belt removal in a very unorthodox procedure...but it's almost as involved as a timing belt job. If you're due for one, this would be the time. Dealer price for replacing thermostat alone is at least $500. T-belt job, including thermostat and waterpump (recommended)is at least $1800. Home mechanic DIY $500 give or take.

Foeglass

you can chance the thermostat without removing the timingbelt on the 32V engines
on the 40V engines however (1999+) you do have to remove them.

Look at the picture where the Thermostat is placed,
In big words all you have to remove are the engine coves and the coolant hoses infront of the belt cover and you have acces to the thermostathousing.
a tip mabey: place some plastic or tape over the timingbelt cover underneath the thermostathousing before you remove it so the coolant doesn't run over the timingbelt.


Remove the front to replace the timingbelt?? i've chanced my belt recently and didn't remove anything from the front apart front the radiator fan. as you can see in the pic.
The Audi workshop manual also doesn't mension it.
And you have enough space to acces everything.

silverd2

My mistake, I was quoting procedure for facelift (40V)... I too, did NOT remove the front of my car for an '01 belt change. I said "most do" , which they do (on 40V), ...And many prefacelifts 32V, for more space....countless write-ups that state that....I disagree, too.
Bentley DOES, though, tell you to remove the front end on 40V engines...I didn't find it necessary, but I'm in the small minority with that opinion.

Thermostat: I said at least "partial" strip down, which you displayed in your photos...no fan, serp belt or covers in the way. I haven't worked on a 32V engine and realize it has a different thermostat housing..but I've seen the location before and have a question:

Have you personally removed the thermostat housing with the degree of stripdown you show? If so, how did you access the lower bolt? As I said, no personal experience with 32V, but I couldn't quite see the lower bolt (as I remember)....AND one 32V owner I talked to, who changed his therm without t-belt removal, told me he had to loosen and pry belt (and back belt cover?) out of the way to access it and move therm housing enough to remove thermostat. I wasn't there, so...

Links below show you the "unorthodox" procedure to do it on a 40V....it is possible, but a pain.

http://www.ltooz.com/ltooz341/item/2...emoving-t-belt

http://forums.quattroworld.com/a8/msgs/25639.phtml

P.S. '99 models still had the 32V engine.

silverd2

First, thanks for chiming in Foeglass...that's why there's more than one of us here.
I AM curious to hear all that's involved to change the 32V thermostat...hidden bolt? etc,...

On T-belt procedures: The funny thing is that early and later D2's have exactly the same space from lock-carrier (radiator) to engine, so plenty of space to do the job...every procedure, tool (including torque wrench) and adjustment...no problem. Bentley gets their info and procedures directly from Audi...the same guide that Audi uses in their shops...along with a price for each step in the procedure, even if it's unnecessary. I not only didn't remove the front end, I didn't use any special timing tools...just marked the crank and cam gears with paint and corresponding marks on the old belt, which I transferred to the new belt. Also didn't even loosen the cam gears...removed old belt, lined up paint marks and slipped new belt back on with no problem, when tensioners were de-tensioned....perfect timing, piece-o-cake.

Audi actually made the belt job on a 40V easier than a 32V...all covers clip off/on, no hoses in front of engine, crank pulley comes off crank gear with allen heads (no need to remove crank bolt, unless the seal's leaking), etc... But Audi's updated procedure in Bentley for 40V's calls to remove the front end. Even Audi techs admit that it's just to add more $$$ to the repair...NOT because anything really changed. I can't believe how many home mechanics do that, too...I consider it a royal unnecessary pain...a complicated procedure by itself, full of potential for collateral damage.

Foeglass

Was not offending you i hope? English isn't my first language.

The thermostat housing is secured with 2 M6 bolts i beleve no hidden bolts, you just have to put some tape or plastic over the timingbelt cover so no coolant runs onto the timingbelt.

I allways use the special tools, with my S8 the timing was off by 1 teeth!! on one of the banks.
And i find that the engines runs smoother with everything lined up 100% after a belt chance.

Its just more work and with the 32v engine because the camtools can be a pain to get lined up properly.
on the 40v engine you have to use the big tool infront of the cam's wich i find is a bit easyer.

It's faster using paint marks and doesn't make aloth of difference if the engine was running good.

My Audi workshop manual doesn't state removing the front, perhaps in the US of outside EU there are differences?

Indeed you are correct. i beleve untill 08-1999 in the pre-facelift, 32v engines were used?

silverd2

No offense at all...quite the contrary. I'm here to learn, as well as share what I know.

With other improvements Audi made for easier maintenance, I wish they had NOT changed the thermostat housing. Even the shortcut method 40V's is major surgery.

My car is on it's 3rd thermostat in 100K miles...luckily the first one failed under warranty and the one I changed failed when I was due for the T-belt change anyway. I enjoy the work and finding ways to simplify the job, without effecting the outcome. Mine was running perfectly before, so I tried to disturb as little as possible and the paint mark method worked perfectly for me.

Again, thanks for the info.

Nothing wrong with your English at all....what country?

Rdizzy

Thanks to all that chimmed in. The issue was the thermostat...I tried to replace it myself but the bolts had some rust and i didn't want to strip them so i purchased the thermostat from Napa for $25.00.(didnt know they carried BEHR thermostats)and a gallon of g12 fluid from Audi for $23.00.
the mechanic did the repair for $90.00 and the car is running great.
The mechanic stated the thermostat was original so mow i want to get the car back to him to do the timing belt within the next couple of weeks the car is at 98,000. he quoted $850.00 to do the belt and water pump...parts included.

Thanks again all

silverd2

Glad you got that fixed and yes you ARE due for a T-belt job. That's a very reasonable price for a difficult job and well under dealer price.

I would question him, however on the quality of the waterpump he's gonna use...this is the weakest point in the T-belt circuit and should be of at least relatively high quality. There are some that are suspiciously cheap and more prone to failure (esp with a new tight belt) than higher quality aftermarket and OEM units. I have always gone with higher priced/quality aftermarkets and had good long term service...no failures ever, so OEM is not necessary, just good quality.

It's always a good idea to change the waterpump at T-belt time, not only because you've already done the major disassembly, but because new timing belts have been known to finish off older waterpumps that seemed fine before...due maybe to tighter new belt, better traction, etc (?)

Rdizzy

Thanks for the info Silverd2

I went to this site...http://AutohausAZ.com
prices seemed very good and the reviews for the site were good.

I wondered if the parts they offered were trully OEM and of good Quality

Any advice?

Thanks

Rdizzy