My 1996 850 Turbo wagon, has 88,000 miles on it. Within the last week it has started making this buzzing/humming noise at the front of the car right after start-up. It does it for about 5-8 minutes, and then all is quiet. the car runs great, but i have been noticing 3-4 drops of oil on the ground under the front as well. I recently changed jobs, and went from commuting 400-600 miles per week to about 50 miles per week total. Would that have anything to do with the noise?

The car is kept in a climate controlled garage most of the time, but sometimes sits outside at night.

Thanks in advance for any advice

Jason