Did you put in a new oil trap/ breaker box when you did the PCV? I think you still might have a clog in your PCV.

Try the blow test. If it passes, at that point it might make sense to move on to doing a leak down test and compression test. Probably a good idea anyway. Unless the car has been seriously neglected I doubt you’ll find a problem with the compression or rings. The white block engines have bottom ends that are typically bulletproof. Usually what happens with them is with very high mileage (200k+) the valve seats start to leak some oil. That happened to my 95 850 at around 230kish.

Do you use any oil? How much? An old school test for the rings is to warm the engine thoroughly then lock into second gear on a downhill, rev the engine to 4000rpm+, hold it for a minute then release. After releasing the accelerator, look out your rear view mirror for oil smoke clouds.

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Will I buy another Volvo??? We'll see....