Previously... we had identified this point of leakage from the cooler area, and eliminated the cooler itself from our enquiries - it pressure tested fine.

With cooler removed, the area looks like this:

And Porsche has been kind enough to give us a clue about one possible source for a leak:

Close up of the cast-in pipe on my engine:

At this point we have a suspect, but no proper smoking gun. Because, on my engine, the side of the cast-in pipe outside the oil cooler cavity is in exactly the same state, and is not leaking.

Still, it can't hurt to follow the procedure in the service bulletin, which can be summarised as "gunk it up".

With the help of those more expert than me (thanks DDK), I realised there was another potential problem in the oil cooler area.

On the left, the studs behind the cooler on my car. On the right, an example picture of what should be there...

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As well as the obvious difference of the domed nut, more importantly the correct washers are thick and have a chamfer on the inside edge to retain an o-ring. Same as all the other stud nuts. My engine had no o-rings.

Correct parts ordered from my OPC and fitted, and, boom!

Leaks are gone.

Phew, simple fix in the end...

The main problem revealed by initial running was a fairly sizeable oil leak. Or leaks.

Not quite a gush, but more of a drip than a weep, if you know what I mean. Seemed to be coming from the oil cooler area:

I had lazily / optimistically just bunged the original oil cooler back in, cleaned but not pressure tested, so the cooler seemed the first likely culprit to check.

Following a modest investment in a Stomski Racing pressure tester (and yes, I do realise there are cheaper ways to achieve the same result, but I can never resist buying another slightly obscure tool...), the result: nope, cooler is fine:

So having established that the cooler itself was probably not the culprit, I disappeared down the rabbit hole of internet wisdom about the cooler-engine seals. Long story short, there are various types:

...and many folks believe that not all types seal properly...

http://forums.pelicanparts.com/porsche-911-technical-forum/795980-oil-leak-dilemma-part-2-damn.html

So I got all excited thinking this might be my problem.

I sent this pic to Barry....

... and proposed that the pattern to the left of the large hole suggests that one of the high pressure seals (at the top, out of shot) has leaked, oil has ended up in the recessed area of the cooler, and made its way out via that blackened channel. Not necessarily during my ownership.

Barry was, as usual, the brains of the party. He pointed out that my leak happened even when turning over on the starter to get a bit of oil pressure before the first run. So at very low oil pressure, maybe 10psi. He wasn't buying my failed seal idea, and when I switched on my brain I had to agree.

So I ordered a new set of seals from my OPC, on the basis that I might as well replace them and the Porsche ones were the most likely to work. For the record, Porsche sent the green type. Many thanks to Paul at OPC Guildford for delivering them FoC. A quick go in the ultrasonic cleaner, and then the cooler went back on the engine:

Where were we? I think the borrowed throttle bodies were on, driveshafts fitted, ready to give the engine a run and try some gentle movement under the car's own steam. So we (meaning Barry and I) gave it a run. Resulting in good news and bad news.

Good: Starts easily, no funny noises, revs cleanly and responsively, good oil pressure, feels fine. When we dumped the oil after a few minutes running everything was nice and clean with no nasties to be found. So the basics seem good - phew! - but doubtless lots of tweaking will be required in due course.

Bad: Well, the day ended with more of this sort of nonsense:

....and the engine back out of the car: