[key_lime]

Thank you everyone for these suggestions

Originally Posted by kk2002s

Thing with fill tube, only if you were adding oil would that come into play

My oil currently sits at the maximum mark shown on the digital readout – maybe this, combined with the G-forces of driving is forcing excess oil back up the tube (and out) ?

Originally Posted by kk2002s

What about before last week, were you seeing oil?

I hadn’t noticed any oil leakage prior to last week, no.

Originally Posted by kk2002s

When car is running how is the vacuum on the oil fill cap when you remove and does the engine run differently?

There is also no discernible change in how the engine runs with or without the oil filler cap, and very little suction at the top of the filler tube in the trunk. I guess this would make sense if I was already losing vacuum downstream? I think it’s a certainty the tube has failed at this point, just a matter of what else

Originally Posted by 78F350

Here's a few pics from the gallery of leaks I've fixed on some of my 986s:

These are very helpful photos, thanks. I agree with you (and everyone else) with respect to cleaning the underside up before trying to fault find any further. I have a new AOS and middle filler tube on order, and will give the underbody a deep clean once I’ve got them fitted

Originally Posted by Geof3

If you do your spark plug tubes be careful you don’t break one…. you do need a tool, no matter what

I have one of these arriving tomorrow after seeing it used in a spark plug tube removal video on youtube. Hopefully it does the trick…