These responses were helpful. But then this raises a few questions. The engine has been producing a whine that rises and falls with rpm, different from the turbo whistle. And mpg has gone from 17 around town to 13.

I had just thought after hearing others post a PCV whine and poor mpg when the PCV system needed serviced that this was the case on my XC90. But if the oil trap wouldn't go bad, then my next question is whether item 15 in the parts diagram would produce these symptoms?

Frankly, I have no interest in servicing the PCV system given that it requires so much digging to get to.

We bought the XC90 at 120k miles, and I changed out fluids for Amsoil which I run faithfully in my other vehicles. So synthetic only for the last 13k miles, unless the previous owner used synthetic, I don't know. I have an oil sample ready to send off to Oil Analyzers, so this will be the first real information I get about the internal health of the engine.
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94 944 na 319,000 and still rolling - 05 XC90 2.5t AWD for the wife