The crankcase ventalation is listerlly pulled right out of the engine on a turbo and then sent right back in and out the exhust, as long as the turbo works right it will pull the pressure out and have it recombust in the chamber and out the exhust and that is done for every fire, now if you think you have a bad motor hence "Rings" you should see white smoke comming from the dipstick area as volvo's tend to let that smoke through normally with good rings youll notice it, check for oil in the pipe which comes accross the top of the valve cover for excessive oil, thats the one which lets the engine breath the legal way. good luck. also keep in mind there is no Brather box or Flame trap on some early turbo models and even later on there still wasnt flame traps this only applies to the turbo models.