I have a 94 850 Turbo and I had a similar noise. My car doesn't have an air pump and yours may not as well. If you have a chance next time you cold morning start your car, go to the engine bay and pull SLIGHTLY on the throttle cable and see if you can pinpoint were the noise is coming from as the engine revs a little (key words "a little"). My noise seemed to be coming from the left side of the engine near the belts. If this is what you experience, then try this fix (it will sound crazy!!). Run synthetic 0w-30 oil in the winter. Ever since I started switching to 0w-30 oil in the winter the noise has pretty much disappeared. I'll maybe get it when the car hasn't been started for a couple of days in the winter. And when I do get it, it goes away within 10 seconds of driving. Just for your information here was my symptoms:
Cold morning start, idle sounds fine.
As I started to drive, and revs start to increase it sounds like a loud low pitch whistle (almost like the car is moaning). Sound is directly related to revs, the higher the revs the louder the moan/whistle until a certain rev where it would stop and return as revs came back down. This would sequence would repeat until the car was somewhat warmed up (first 1-2 min of driving).

Hope this helps and let me know what you find out.

Scott

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Scott K - 1994 850 Turbo

Hi Mike,

Hope this isn't it, because it is expensive. My 98 AWD was doing the same thing. I could hear that the sound was coming from under the battery. Investigation showed an air pump there, that only comes on when the temp is very cold.

Replacement was free under extended warranty, but would have cost $300-$400, I am told.

I have read posts where people have removed and repaired the air pump, then drilled a small hole in the bottom to get rid of the moisture that eventually freezes up the bearings. If you can free up the squealing bearings, apparently the pump will work quite a while.

Good luck.

Mike Harris in Sandy Eggo, soon to be Sedona, AZ.

I have had the same noise on my wife's '93 850 GLT ever since we bought it a year ago. The noise only happens in the winter and goes away once the weather turns warm. I had the belt tensioner replaced as well as the serpentine belt, although the noise didn't sound like it was coming from the belts. A very unique sound, like the sound you get blowing over the top of a empty soda bottle. I've sort of got used to it now, it goes away after a couple of minutes of driving. There has been some discussion about this on this forum, and someone mentioned a vaccuum seal leak. Sorry, I know this doesn't answer your question, but let's you know you're not alone with this odd noise.