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Q: There is a unkwon sound when ac is on.when ac off sound is small.is it problem of crank pulley

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Fan belt and power belt is ok.no issue in adjusters.when load is increase sound incresing.what is the problem.

My car has 100000 miles.
My car has an automatic transmission.

Hello, thank you for writing in. The vehicle is likely having an issue with the A/C compressor pulley. It explains the noise being relevant to engine speed and load. With that being said, the pulley and the compressor may both need to be replaced. The extent of damage done will need to be assessed. You will want to replace the belt at the same time if in a position to do so. The noise may be coming from the bearing inside of the pulley, or the extra tension that is being applied to the belt system from compressor failure. For more diagnostic help, contact our service department to schedule an appointment.

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