My 1991 560SEL with 134K mi. has developed a shrill howl from the passenger's side vents when the car is started cold in the morning. It is particularly noticable when it is a frigid morning. After 1-2 min. it quiets down but there remains a whirring and buzzing coming from behind the region of the passenger's airbag. This sound is at a different pitch and volume from the sound of the blower, and remains even when I press the O button on the climate control console. Is there a little vacuum motor in there that is giving up the ghost?

Thanks for any insights.

Best,

Stu

__________________
Stu Selip
CTO
New Age Network, Inc.
111 B'way, Suite 1602
New York, NY, 10006
631-697-5713