Can an engine force oil through a good AOS?

[Gelbster]

Originally Posted by JFP in PA

It can, these engines are known to hold a lot of oil in the cam covers at speed, which is why the high performance versions in the 996's known as the X51 package used extra oil scavenging pumps in the cam covers and a "northwest passage" oil line to get the oil back into the sump.

Thanks for this explanation. I did not know this about the X51. I had only read the 'sexy' parts of the X51 kit - sports exhaust ,extra mystery power and cost. I have never seen a comprehensive list of all the X51 differences. The extra scavenge pumps and N.W. passage certainly seem desirable and rather inexpensive to have made a standard feature.I understand why it would be expensive as a Dealer installed retrofit/option.
But for the P.O.'s question it does hint at an (unlikely?) cause