So for the last several months my engine has made a rhythmic squeaking noise while at idle. It finally got to me today, so I went under the hood to see if I could isolate the source. I decided it was coming from the pulley on the alternator, which left me wondering what to do. For some reason, I decided to hit it with a blast of air, thinking that the noise would change and I'd have a definite answer as to the source. A huge cloud of dust came flying out of the pulley and the plastic cover that covers the top half of it, and the squeaking stopped.
So problem solved, but this left me wondering: would it be advisable to spray some WD-40 in there to clean out the dust/dirt, and if so, should it be done on a regular basis?