Sump looks damp

[Jepor]

Hey all 

I was just having a look at my inner cv joint earlier and I could see passed it to a sump , not sure if these is the main oil sump or the transmission sump , but I noticed it looked a bit damp around it , just wondering is this a bit of sweating , the car is driving well and have no oil lights coming on , it's been 45000km since last auto transmission service  . The car is a 2015 audi a6 c7 s tronic .  

 

Thanks 

[cliffcoggin]

There's no doubt it is leaking oil from somewhere. That will be expensive repair, so unless you need to top up frequently I suggest you ignore it for now.

[Jepor]

Never get an alarm in the car for low level gearbox oil , and no trace of any oil on the ground where i park , think it might just be a case of a sloppy mechanic when last serviced , which was 45000 km ago . And haven't had to top it up since . 

[cliffcoggin]

Fair enough, but if you began to see oil spots on the ground where you park don't delay doing something about it.

[Jepor]

Ya will do thanks . I'd imagine if it was leaking for a long time I'd have some alarm by now. 

[cliffcoggin]

I am not aware of alarms for gearbox oil level, only for engine oil level, but maybe I am out of date on that score. Maybe somebody else will chip in with an opinion.

[Jepor]

Did a bit of further investigation and something the scares the s**t outta me , what looks like a small hairline crack along the metal over the plastic sump , it doesn't look like oil is leaking out of it looks dry around it , can these cases get small hairline cracks that don't go the whole way through , so they actually don't leak ?  Surely the would be fluid marks running down from the crack , and there is also never oil on ground underneath the sump 

[Jepor]

Also the car is driving perfect,  no skipping gears , smooth gear changes , everything seems normal . 

[Jepor]

Looking at it closely I think it's just staining and not actually a deep crack , it's like the edges of wet staining.  The car is driving to well for me to believe that the gearbox is cracked,  When I look there is no sign of oil leaking down from the marks . That surly would suggest that it's not leaving oil out  .

[cliffcoggin]

Imperfections in the sand mould can often create surface imperfections in the metal that look like cracks in the casting, or it may actually be a real crack. The only way to be certain is to take it off, clean it thoroughly, and apply a penetrating crack detector dye.

[Jepor]

To be honest at this stage I don't think it's a crack , it's showing no sign of oil coming through it , and like I said there is absolutely no sign of oil anywhere i park . Also surly if it was leaking out oil there would be traces of it the whole way along the bottom side of the car , of which there's none . And also the car is driving extremely well surly a crack gearbox would show alot of symptoms.  

Thanks 

[Jepor]

I think this stage im just paranoid about my A6 , I've waited for years to get one as I could never afford one before in my life and I have now finally got the one I wanted " my dream machine " ( a 10 year old a6 I suppose some would say it's not much of a dream ) ,

but not that I have it im listening out for every knock and click and i find myself actually to nervous to enjoy it , with the fear of a major bill . And the thought of major gearbox damage has me actually sick to my stomach. 

I think it's time I just drive it and enjoy it , because it is a joy to drive . 

Thanks