What is your diagnosis?

[husker boxster]

Isn't it possible the AOS crapped out? If there's oil on top of the engine, chances are good it's the AOS.

[Dale_K]

The fact that the failure was silent is a clue but it might not be a good sign. If the motor won't crank it might have seized due to a major oil leak that led to lubrication failure (just a guess).

If it cranks and sounds normal (normal cranking speed indicating good compression) then maybe AOS which led to MAF contamination and RMS failure (another guess, but less likely than the first one).

I'm no expert, so take this with a grain of salt.

[silverboxter]

The AOS was replaced 10,000 miles ago at 120,000. It allowed oil into the crankcase and seized the engine. Oil was dripping out of the exhaust. O2 sensors were replaced. Guessing that rules out the AOS.

Had a restless night preparing myself for the worst.

[clickman]

If a previous AOS incident hydrolocked the engine, you may have had some internal damage that took this long to finally come home to roost.

[Jaxonalden]

Good luck on the diagnosis, an engine that looses power is by no way a good thing..unless the intake air was completely choked off.