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2002 Z06 150K miles on the original motor - stock drivetrain.
A couple of times now, when I start the car dead cold I'm getting this odd whistling sound. After 30 seconds of idle it drops away. I thought it might have been an alternator bearing going away, but after swapping in a new one... that wasn't it.
Managed to catch the sound on video. Any ideas
Your secondary AIR pump located in that area operates for around 30 seconds when the car is first started…that’s probably the sound you are hearing..to verify remove fuse 50 (AIR PMP) in the underhood fuse block and see if the sound disappears…it is a maxifuse which are one of the large ones circled in the picture below….video below to show better location.
Noise diag help
