Problem definition and background: Sudden onset of whining noise on a 2007 Honda Accord Ex coupe.
1)Whining noise becomes louder when accelerating.
2)Whining noise is more pronounced when AC is turned off.
- Using a mechanics stethoscope, it was discovered that the noise comes on immediately when the AC clutch is disengaged and is greatly reduced/disappears immediately when the AC clutch engages.
4)The whining noise is the loudest at the left end of the compressor or the right side of the alternator. I was not able to distinguish whether one is louder than the other.
Interestingly, however, the noise is not heard when placing the stethoscope on the AC clutch.
5)I tried to put WD 40 on all of the pulleys except the crank pulley and could not come to a conclusion as to whether it had any effect on the noise. The noise seems to be slightly reduced after spraying the compressor pulley but not a 100% sure of whether this is the case.
6)The whining noise is only present in park or neutral mode. It disappears when the gear is shifted to park or neutral (while stationary).
Summary: Whining noise seems to be at the alternator, compressor or somewhere in between but I cannot tell for sure. I tried to apply wd-40 but the results were not conclusive. How can I tell whether the noise is coming from the alternator, compressor, or both or something in between?