Motor noise when A/C is on on 1996 Lexus ES300

My 96 ES300 runs perfect and everything works great except for this noise coming from the hood when A/C is on and the car is accelerated, meaning noise occurs only when I step on the gas pedal. This noise sounds very much like engine revving sound. The thing is A/C works fine. What could be wrong, and what kind of repair cost should I expect?

1 answer 7 comments
Could be the engine fan. When the a/c is on the fan is engaged.
What kind of cost am I looking at if I need to replace the engine fan?
This car has an electric fan so I may be wrong about the noise. We would have to listen to the car to be sure.
In case I need to replace the A/C compressor, and I bring the part that I buy on internet, what would you charge for replacing (labor only) the A/C compressor and clutch?
$413 plus evacuate and recharge $179
Thanks. wow.. that's lot more expensive labor than the repairpal estimate..
If you want to get your own parts we increase the labor to recover the profit we make on the parts.
I have to say, you seem very honest. Thanks.