Volvo Repair: S60 Volvo idle vibration, saab specialists, volvo saab

Question
 Roger, my daughter recently bought an S60 program car with about 26k on it Six months and 6k later it has a vibration when idling. It idles at 600rpm and if if I hold the brake and increase idle speed to 800rpm it goes away.I have had the car to 2 Atlanta area dealers with frustrating results. They first replaced the fuel pump and then the motor mounts with no help.They now tell me that it is due to it being a 5 cyl and the vibration we experience is normal for this car. It is much worse in cold weather but the first dealer said they didn't feel anything then. 2 or 3 weeks later at the 2nd dealer the weather has warmed here and this vibration is much less but still not acceptable for a car like this. Where can I turn or what should I try?

Answer
Pete, first of all the idle is too low.  should normally be at 800-900.  Does it change at all when the compressor is engaged? If the Dealer cannot solve this problem. they MUST get Volvo tech services involved. Im assuming its still under warranty.  If they cant help then I would take the car to Atlanta Volvo-saab specialists in Norcross.  Ive heard good things about those guys. Roger