Engine oil leak help

[laalves]

For years now (5+), I have a small oil leak on my MY02 996TT Tip. Oddly enough, It has actually improved after I replaced the engine mounts (were and are Porsche originals) and the transmission support, also with a Porsche original.

I say the leak improved because I used to find drops oil on my garage floor and they were getting larger. After I replaced the above, they stopped...

Anyway, I'd like to take care of this, thus I'm posting a photo, hoping to get some clues of what should I be looking for, what is the most likely culprit considering where the oil shows up and what should I do to positively identify the source.

It clearly comes from the left side of the car, somewhere above on the rear side of the engine. What is there that can cause this?

Edited June 22, 2020 by laalves

[laalves]

After looking at the engine a bit more carefully, it appears it is the timing chain tensioner bolt that is actually visible in the photo. I was thinking it was coming from higher above but it looks like that bolt is the culprit. Looking at the parts catalog, I can identify it but can't see any o-ring. It looks like it has a crush washer rather than an o-ring though, unless there's one in a flange recess. 

In 911uk.com, another fellow has the same but does not know the procedure to change this. Looking at the manual, all the mention is taking the complete assembly apart, engine removed. It would appear the camshafts would have to be locked.

I'm tempted to check the torque (the manual says 25Nm) but I won't until I learn more, camshafts are not the sort of thing I like to touch without knowing exactly what I'm doing and its consequences. Off course, torque check would only slow the leak, at best, if anything.

In the parts catalog, it is item 13 of illustration 103-15, P/N 993 105 275 52. It says "Information available", i.e, there is a related TSB. Anybody knows anything about this? Any idea on how to replace this part as I suppose the tensioner shaft and/or camshafts must be locked in position?

Edited June 22, 2020 by laalves

[laalves]

As a quick update, I tightened the bolt by 90º and cleaned the engine bottom with brake cleaner. 300km later it's still clean. I don't believe in miracle cures so I guess this is only a temporary fix but it is working for the moment.

[laalves]

Another update, there is another, smaller leak, more like a sweat. It's coming from the right side and is inaccessible due to the water pump manifold. To have a go at this, would require quite a bit of disassembly so I guess I will live with this, unless it does get worse. Or maybe with thin locking-pliers I would manage to give the bolt a quarter turn as another stop-gap measure, not best practice, I know but perhaps better than leaving it as it is? Any views?

 

I changed the oil last week and changed from Mobil 1 0w40 to 5w50 which is more suited to my climate anyhow and maybe (a small maybe) the higher viscosity might also help a little bit with slowing down the progress.