In reading this old topic today, I noticed a few things.
That is; blowing into the intake-to-manifold tube only tests one of three valves inside the PCV. It tests if one of the PCV valves contains boost when present. If you can blow through it, then you lose boost. The other two are what seal the crankcase when in vacuum. The diaphragm and recycle valve are shut to apply the vacuum to the crankcase. If they do not seal, then vacuum applied by the intake manifold will suck air through the PCV from the turbo inlet. Testing it requires blowing into both the intake side valve and the recycle to turbo inlet valve...both should seal. Then the diaphragm must be removed and inspected. You can check if vacuum is strong with the oil filler cap removed or the dipstick removed, but you do not know the level of vacuum without a gauge. Or, use a gauge to check the vacuum. If vacuum level is normal, the the PCV is working fine in vacuum mode.
