Name That Oil Leak
 

Well, I discovered some oil on the driveway and garage today. After some investigating this is what I found... So I assume it's the rear main seal and it just so happens I started towing a 4000lb camper behind it. The car has 127k on it and the warranty work was accomplished in February 2019 at 68K so I'm SOL for a dieselgate claim. Anyone have experience changing a rear main seal and what could we expect doing this work? I have a lot of experience working on my stuff but I've never pulled an Audi transmission and I'm planning to do this with some help. -2011 Q7 TDI-

https://cimg3.ibsrv.net/gimg/www.aud...e9e4c76ff1.jpg

Either the rear main or the "upper oil sump", which is located above the RMS. It's not possible to tell which it is unless you can get a scope in there or separate the engine.

It looks extremely minor to me, so I'd not worry about it. I know people's tolerance level for leaks varies, though. I tried very hard to get mine addressed while it was under the extended warranty, as it leaked like this for the entire time, and I finally just gave up on it. My car is right at 150,000 miles now, and it still leaks here, but the quantity is only slightly more now than it was 75,000 miles ago. If it keeps this way, I'll deal with it if/when something more significant happens, like a timing chain issue.

I'm with Wes, except I'd try a leak sealer product, which can work to moderate the leak on an oil seal, but not for gaskets, etc. Knock on wood, but neither of our TDIs has any oil leaks.

I shall name the leak "bobby"! ;)

For the CATA, while the leak may appear to be rear main, it is likely oil coming from above. I had a similar leak that looked like rear main, it was the PCV connection to the turbo inlet....running down the back of the engine. Valve covers are also typical. CATA doesn't have the same number of upper oil pan leaks that the Gen 2 has.

As for dropping the transmission, it is a huge pain. I dropped the trans out last year and it wasn't fun, LOTS of stuff has to come out. Next time I will drop the engine + trans on the front suspension. Get ahold of ELSA and take a look at the procedure.

Definitely look up higher on the engine (backside of engine especially) and also around the valve-cover areas to see if oil is visible coming downwards from any of those areas. That happened on our '10 when turbo oil seals began to fail, oil entered the 'turbo-pipe'/intercooler system, and eventually leaked out top,rear of engine where turbo-pipe meets a juncture, etc. The oil then fouled most everything below/behind where it was leaking from, etc., and so it appeared to have the 'classic' oil leaks, but it didn't. It was just the turbo giving out as the root-cause.

What is a good leak fix product? I have a little oil leaking as well. not much and I'm just going to let it ride until it becomes a larger problem.
I saw a prducct called "Blue Devel Pour and Go Rear Main sealer", has anyone heard of that or tried it?

I'll give a one month update on this thing.... It stopped leaking.... I have some theories as to why it happened and have a potential solution. I was towing a camper, not anything outrageous- 3500lbs dry and probably 3800 loaded. Coming down hill I used the transmission to not burn up my brakes but that caused the case pressure to go way up from normal load for an extended period of time. My solution will be to direct vent the case and see if that fixes the problem. I'll report back next time the camper goes out after this mod.

Certainly a good hypothesis, that's how I run when towing. Just be careful, venting the PCV will burn up more oil.

AT -205 re-seal stops leaks is highly rated

I had that same leak in both my 2013 Q7 and 2014 A8 TDIs. Both were covered by my dealer under the TDI diesel gate warranty. There is a TSB regarding this leak, and it requires pulling the motor and several days of work/several thousands in parts/labor to replace.

https://static.nhtsa.gov/odi/tsbs/20...81641-0699.pdf

If you're still inside your 10 year/120k miles or your 4yr/48k extended, I'd recommend getting it to your dealer sooner rather than later. Usually they'll want to clean it once, then have you show the leak has returned before they agree to get it fixed. Mine would usually return to a leak visible within 700 miles.