I've got a 98 S70 NT. When I drive it out of the garage and hit the end of my driveway, I hear a loud whistling sound coming from the driver's side in the engine bay. It whistles loudly for about 15 seconds or so, then winds down like a siren does. It's been going on for awhile, but seems more pronounced now, maybe due to cold weather. I also have heard it come on while I'm idling at a stoplight for a period of time. It's pretty loud, and does wind down, but I doubt it would be considered normal. Recent work includes new distributor and wires. Any ideas?