I recently picked up a 1991 240 wagon, 5speed with 225,000. It's in pretty good shape. I have worked through various resolvable issues with it, but I can not figure out the high pitched shriek that starts when traveling 65mph or faster. It emanates from inside the left dashboard directly in from of the instrument panel. The sound is similar to the high pitched sound of a troubled blower motor. This car's blower works and sounds perfectly fine. I have duct taped around the entire windshield thinking about an air leak problem with no resolve. The front end is true, perfectly aligned and tires all balanced. That should not be a contributing factor. I have searched the internet but have not found anything too helpful. Any ideas would be greatly appreciate. The noise makes highway driving unbearable. Thank you, thank you, thank you!!