hunterp27

MP4.2
Thanks for the ideas. As I look at your picture I can see that our oil pans are similar but not the same. It does however look as if they are similar enough that you will/would have the same issue when trying to remove the row of bolts along the back row. My bolts are standard heads, not allen or torx.......which certainly makes things easier. I was able to get things reassembled last night and was able to securely tighten all the bolts including the difficult to reach ones.
As to using the sealant sparingly, I applied it in the small channels on the pan and around each bolt hole. Very little "squish" from pressing the pan into place. All-in-all an easy do it yourself job but now to the disappointing realization: this may not have been where the leak was coming from. The reason I say this as I was reassembling I noticed three places where residual oil from the dry motor was still seeping down and bleeding onto the surface of the block where the pan meets the block. Two of those "bleeds" where definitely coming from internal origin as I could see them, but the third was different. Oil just kept appearing on the 3/4 inch wide surface ever so slightly. I am almost certain it was coming from the outside and seeping down and then coming across the surface. That means something bolted to the outside is leaking. Given the limited visibility to the area, it won't be confirmed until I load the engine with oil and look for leaks. Sorta bummed after doing the job. There was no way to know this ahead of time however given that everything was oil soaked in that same area and no amount of wiping it clean and visually inspecting was gonna reveal the origin as internal or external.

MP4.2+6.0

Search on AW is often mediocre, but if you go into Google with key words and site reference you might turn up something. Something like: "oil leak" D3 S8 site:audiworld.com You also have the C6 generation S6 with the same motor you can poke at.

I vaguely remember a post or two that started with some kind of problem where the S8 engine pressurized internally and started blowing out things/causng leaks. I think there may be a post or two that also had leaks in hard to figure out areas in the back.

FWIW, the oft generic one for any of these is off the back corner of a valve cover and then dripping all the way down. That one you can often feel with your fingertips on a (cold) motor by reaching into back area. May need to pull intake air boxes either for that or to see better back there in general. Getting air boxes out way increases what you can see in general, and I find is often a precursor to work on anything close to the back of the motor if the issue isn't right on top. Passenger side is easy in full. Driver's side is a b^$%$ to pull lower half because of the secondary air pump hose connection on the bottom; pretty much have to loosen fender liner toward front to reach in there and squeeze the connector to get it off. Even just the easy upper half of boxes where you get at the air filters opens up a lot though.

As an aside to that, if you haven't done it yet, you will see the filters get surprisingly dirty even at half their life. Probably the "ram air effect" of the very straight back direct cold air feed from the grille that they (S8s and W12s) have. Thus, if you haven't been in there for a while or ever, blow them out while you are at it any time you have the boxes open. I've added that to my "half life" maintenance at 20K/every other oil change step.