Oil around the filler cap

[Orman]

Hi, 

 

So I noticed there has been oil leaking on top of the valve cover from somewhere, and there are small puddles of oil collected around each injector. I looked at the filler cap as that is the highest point on the valve cover, and I saw oil around the filler cap on the rubber lip surrounding it. I bought a new filler cap and fitted it and wiped off the oil around it, but I can see there is now still oil on that rubber seal around the cap, even with the new one fitted. But I can’t physically see anything that is leaking or bubbling. Will take some pictures tomorrow in daylight and post them here. Any suggestions?

 

it’s an Octavia vRS 2.0 TDI CUPA -2015, with 240k km

Edited 5 January, 2023 by Orman

[KenONeill]

2 hours ago, Orman said:

But I can’t physically see anything that is leaking or bubbling. Will take some pictures tomorrow in daylight and post them here. Any suggestions?

Check the oil level.

[Orman]

1 minute ago, KenONeill said:

Check the oil level.

I did, after getting a check oil level message today, it was halfway between low and full, so I topped it up some. I just recently replaced the filler cap and I never got around to topping up the oil after that.

 

But obviously I will be losing oil, since there is an oil leak from somewhere. I’m just not too confident anymore that it’s from the filler cap, but not sure why there is still oil on the rubber lip around it after replacing the cap. Unless it’s leaking from the filler neck.

[ords]

Run the engine with filler cap off and see if there are any or excessive fumes escaping. Could be too much pressure  building up.

[Orman]

6 minutes ago, ords said:

Run the engine with filler cap off and see if there are any or excessive fumes escaping. Could be too much pressure  building up.

I’ll try running the engine a bit with filler cap off. I did notice fumes coming out when I removed filler cap though, after shutting off the engine, but it was very mild. 
 

Could it be PCV valve?

[Orman]

[docx]

Have you finded a solution for your problem? It seems to me that I have same problem, I've tried to switch Golf 7 cap with Kodiaq's to see if it helps

[indars]

06K 103 485 D last revision of this cap, I think. With D in the end.

Installed it on 2.0TDI on Octy Mk3 and Golf Mk7. No leaks so far.

Tip: install oil cap with dry contact area (rubber vs plastic inlet tube).

[docx]

I can confirm it also that D revision fixed the problem