Oil leak on cat?
 

I appear to have a new oil leak, looks like it's a very small leak that is coming from the back of the tranny where it meets the drive shaft and it is dripping down onto the catalytic converter. Strange as the fluid appears to be motor oil yellow, not tranny fluid red, so perhaps it's just some oil making it's way from the other large leak I have on the left side of the engine / cylinder head?

The transmission was replaced in 2009 and I've only done about 15k since then. If it's the tranny then this may be the end of this car but please say no. I fell like on the guys on Top Gear UK when they have a challenge and the producers bring along a ****ty car that's seen lurking in the background to be driven when one of their old beaters breaks down - in my case it's a 2002 Outback .... please don't die car!

I killed the tranny in 2009 by getting stuck in a mud puddle and slamming the transmission into drive and reverse multiple times in an attempt to get out - well at least I'm sure it added to its demise. In March last year I got stuck in a small snow drift but was very carful not to do the same but perhaps I wasn't careful enough.

It's gear oil from the center (torsen) differential...VERY common leak on these cars...I've changed my seal a few times. Leaking onto the left cat, I assume(?)...and smells like a rubber skunk burning :)

No emergency...the diffs can run low for long periods with no ill effects or noises.

The output flange seal (about $20) is the culprit.

Here ya go >>>

http://audipages.com/Tech_Articles/a...placement.html

Exellent news, looks like a simple fix but not sure how easy it is without a lift.

I also noticed that one of the bolts and a spring that supports the cat is missing too - see my screen grab attachment. Do you know what what the part number is for the bolt and spring?

Thanks again for all your help over the years!

Here ya go >>>

http://i1217.photobucket.com/albums/...4.jpg~original

In desperation I called the shop that did the transmission exchange in 2009 and they agreed to fix it for free! So now she's fixed but I still have a big leak at the engine rear main oil seal they told me but she lives to drive another day! Just glad that smell has gone, I hope!

Try adding a full bottle of this to your engine oil about 500 miles before your next oil change....it should help slow the rear seal leak.

It's great stuff for ANY rubber part...windshield wiper blades, o-rings, etc..

I've use this on a few engines with great success at slowing or stopping valve stem seal leaks >>>

Ok so I noticed that I still have smoke coming from the muffler area so took a look underneath the car.

Don't look like they removed the muffler ??? How did that change the seal then ??? Did they change it, they did the work for free so perhaps they didn't ! They did replace the missing bolt and spring.

If they used the Audi pages method they would have t removed the left cat - these bolts are rusted solid. So they have another way then :) perhaps they removed the engine and tranny in the 3 hours they had the car or perhaps the have another way? Hmmmm

Well, in a facelift A8 (mine...'01) the seal can be "easily" (tight but doable) changed with all exhaust in place...I've done it a few times in a gravel driveway, with just one jack. This is because, unlike PFL A8's and all D2 S8's, the FL D2 A8 has side-by-side cats which offer much more working room at the rear of the transaxle. PFL A8 and S8 have staggered cats that leave little space here. BUT, up on a lift, it may be possible to change the output flange seal with exhaust in place...really not sure, but if there was a shortcut possible, they'd take it. Even dealers (in spite of what their itemized labor bill states), never detach the exhaust to change the seals in FL A8's, but don't know about the staggered version in other models.

But I assume they'd have to remove the heat shield and it looks like it was not removed when looking at the bolts that secure it, they are rusted and don't look a wrench has been used on them.

Yep, heat shield MUST come off.