Volvo: VOLVO S 80, volvo s 80, engine seals

Question
I HAVE A 2002 VOLVO S 80. SQUEALING NOISE UNDER HOOD.  NOT BELTS OR TIMING CHAIN. STARTS APPROX. 2 MINUTES AFTER STARTING CAR.  STOPS AFTER IDLING FOR A FEW MINUTES IN PARK.  NOISE PRESENT WHILE AIR/COND ON OR OFF.  AT SHOP W/MECHANIC.  NO ANSWER.  POSS RADIATOR FAN?  

Answer
Gary,
While it is making the noise go out and pull the dip stick or remove the oil cap. If the noise stops it is very possible that the breather box (PCV) is blocked up and will need replacing. When the breather is plugged a vacuum is created in the crankcase and sucks air in passed engine seals causing the whistle.