boomkaffe

yes it is. but water will only had 60-70 degrees. after this change the car run only 10 km then its 90.

right2bear

Good to know. Thank you for the input. Unfortunately I think I will just have to replace one or the other and see if it fixes my problem. Hate trial and error on this car, can break the bank.

Sci-fi_Wasabi

I have a diy with pics on how to change the coolant on a 09 FSI v8. the 5th picture down shows the thermostat housing and temp sensor wire sticking out and one of the bleeder/drain screws(yes its in the front of the engine, low down just behind the radiator). It is quite accessible from below. I think audi sells the thermostat+plastic housing as one piece, if you want to go that route to make sure everything is new when you replace it.. the part number is also pictured in my images.
Anyway, remove a couple hoses and the housing, ... hardest part will be getting that stupid under carriage splash shielding back on!

https://www.audiworld.com/forums/a8-...edure-2878770/

right2bear

Perfect, thank you for the input. I think I am going to purchase the housing and everything from ECS since I need an oil change kit anyway and go that route to start. Hopefully fixes my one problem. Just glad it's not behind the timing belt like the port motor. Next on the list is a new air compressor I believe, starting to get a little noisy and not functioning properly. Thanks again everyone and will try to respond with results after replacement is done.

MP4.2+6.0

New compressor would be painful. See my earlier post. That is tied into gear drive. Not a slam bang its out then in by any means. Step one is like, support engine as a clue--it is really hemmed in by the combination of the subframe and the motor mount. Look at it when under there for the thermo and oil change to get a sense. If you are pulling thermo, I would get enough coolant of the proper type (G12++/G13) to do a complete change. With thermo that low down you are basically backing into it anyway.

Way, way before thinking compressor change is to get refrigerant checked. By now it has likely lost enough to be getting marginal. Same experience I had with my 2006 W12 maybe 4 or 5 years ago now. Other board members who have bothered to have it checked correctly have often found the same. Those posts are a lot more common by summer though so stay tuned for the upcoming season of them--for most of us in Northern Hemisphere. You need to have refrigerant checked/done by weight by evacuating and then refilling. Mine was almost half down. Not a big deal, and any shop that handles A/C can do it; there is no magic Audi dealer fairy dust magic here. Don't be tempted go for the "cheap" can stuff. Good (bad) way to blow the compressor, and then you would indeed find out it is no fun to deal with that gear drive stuff, and spend 20x-50x or more than the seemed-like-a-good-idea-at-the-time can.

From the pictures, I think that thermo is one of the MAP ones--electrically assisted--like my W12 was and I think S8's are. You can see the wiring plug in one of the pics. For both the thermo and the A/C, scanning for codes and looking at operating parameters (measuring blocks) might yield you some diagnostic info. Sometimes there are sensor issues in the HVAC system too, which you should definitely see in a scan.

right2bear

Sorry, miscommunication. I was talking about needing a new air compressor for the adaptive air suspension, not the air conditioner compressor. Completely agree with that would be a little overkill before checking refrigerant first. Air compressor is just not pumping enough PSI and occasionally throws codes as implausible signals.

JulianHicks

Hi 'BoomKaffe', thanks for this photo as I seem to have the same problem you describe that was fixed by replacing this inline thermostat.

I presume this was taken from underneath the car with the cover taken off?

Which side of the car is it though? [The workshop manuals for the A8 don't seem mto describe this part and how to replace it]

Julian

MP4.2+6.0

FWIW, the picture is in the area of the transmission cooler, which in tuen is bolted right to the bottom of the transmission--in front of the pan and behind the front diff area. If you have one, the thermostat is a cartridge type is simply encased in the black plastic fitting you see in the pic. It is sold as one part, so you don't disassemble. Just remove the two squeeze clamps on the ends and swap out. Simple as that, other than trying to minimize cooling loss (if not draining) and then bleeding system.

The W12's have it too, but it really isn't documented. Some of the Scandinavian W12'ers found it could really affect heater output and general operating temp in very cold conditions. I got the number off the part itself and then traced the listing back to a D3 S8 fitment where it was shown.

Drak517

heyy i hope ur still on this i have 07 audi a8 replaced every thang been looken at this where dose this hook up at mine aint hook up but on on one end to the siver box?

Jaseriii

where can i find it