My T-bird has a tendency to make loud howling noises intermittently when idling and sometimes at speed, when it does so during idling, it often stalls, no indicator lights are on and all the auges read normal
howling/humming noises on 1996 Ford Thunderbird
I have an idea -- The noise, sometimes described a "hooting" noise, would be a sticking idle air control valve. This is not terribly uncommon. The noise is basically the resonating of the buzzing of the sticking valve amplified through the intake manifold and air box.