Volvo Repair: volvo s 80, flame trap, volvo s 80

Question
i have a 2002 s80.  squealing noise under the hood.  not belts or timing chain. starts to make noise approx 2 minutes after starting car. noise is present when air/cond off or on, while idling for a few minutes.  then stops. car in shop for a week.  mechanic had no answers.

Answer
Gary, What it may be is if your car has it, The vacuum diaphragm on the flame trap box makes sort of a squeel noise but it usually would keep doing it and not stop.  But I have seen it do that symptom also.  Check under the intake manifold and see what kind of box setup you have and get back to me. Roger