High frequency noise at high RPMs

[kdog]

The car runs and accelerates fine. The issue is at highway speeds(<3000rpms in 5th gear) I am hearing a steady high pitch noise. I only hear the noise when pressing the throttle. As soon as I let off the gas, the noise stops. Touch the gas, noise starts. The red indicator light on the Tach started flickering on and off at the same time I started hearing the noise. Any thoughts?

[So Cal Mark]

the red light is a charging system warning, so I'd check the alternator mounting

[kdog]

Checked the alternator mount this morning. Tightened up the bolts, checked the belt. Belt looks fine. Drove 35 mi to work this morning, no red light. However the sound persists. It almost sounds like turbo spooling. I will check trans fluid and drive axel. Only makes the noise when there is a load.

[mbouse]

hmmm.... not a bearing noise from under the hood? like the alternator shaft bearing or the water pump?

will it make the noise when the car is parked, at high rpm? if so, remove the v-belt and see if the sound goes away.

[kdog]

It does not make the noise when parked, only with a load. I checked the U-joint, looks good. It has no play what so ever. The flexible rubber boot is showing some minor stress. Could that boot be the problem? Also there is a movement in the boot that the drive shaft goes through right near the u-joint. It looks like a rubber boot with a large bearing inside that houses the drive shaft. Should there be movement (shock absorption)? Anything else in the drivetrain?