Oil leaking from manufactured hole in engine block

[James Goddard]

We've got a 2017 S4 Avant that went to the main dealer with a small oil leak. In their attempt to solve the leak, they completed a diagnosis, replaced the casings and seals around the timing chains, then replaced the sump ... then found a manufactured hole in the engine block that was leaking the oil ... and told us it now needs a new engine! Has anyone experienced any similar tragedy?

[James Goddard]

And here's a photo of the 'hole' in the engine block - any thoughts would be really appreciated.

[cliffcoggin]

I have no idea what the hole is for, but it does appear to have a plug in it. Is that plug metal or rubber? Does it have a hex top or slot to allow it to be screwed in? Whatever the reason for its existence there must be a way to seal it that does not involve another engine.

[James Goddard]

Hi Cliff  Thanks for the post - sadly, no plug in it and no-one including the manufacturer's technical department seems to know why it's there or what purpose it serves ... all ideas welcome.

[Magnet]

Hello James,

If it were mine, I would be carefully measuring the diameter of the hole and searching for a suitable (tight fitting) plastic plug, and temporarily blank off the hole to see what happens. Take care that (1) the plug is a tight - ideally tapered fit - to ensure there is no chance of it entering the engine. (2) It can be removed without too much fuss. 
Perhaps you could let us know how you get on James.

Kind regards,

Gareth. 

[cliffcoggin]

1 hour ago, James Goddard said:

Thanks for the post - sadly, no plug in it 

Sorry, the black dot in your picture looked like a plug. Is the hole round or rough? Threaded or smooth? Parallel or tapered? Is the metal around it cracked?

How best to repair it depends on what the hole leads into. 

[spartacus 68]

Speak to Tomas at VAG Technic. Oxfordshire to Dudley is about 1hr 30mins away. They drop performance engines all the time and know their way around S4. I’m sure there’s logical explanation.

[James Goddard]

Massive thanks to Richard aka Spartacus 68 for recommending Tomas at VAG Technic who is very familiar with this problem and can fix it 🙂

[cliffcoggin]

Please do tell us what the hole is intended for, and what needs to be done about it.