I don't think the noise is coming from the pulley. The pumps are just noisey.

When the pulley goes out, you'll know it. The car will be basically inoperable. It will make a horrible screeching noise, as if you were choking a rooster.

I drove mine when the pulley bearing was on its way out, and is I drove through a supermarket parking lot, people were putting their hands over their ears.

By the time I finally arrive at my tech's shop, the pulley was emitting a burning smell. The pulley bearing was basically fried, and I really should've had the car towed.

When the new pulley was installed, the pump was still as noisey as it was before.

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".