QuestionI just replace all three belt( alternator, power steering, idler, but it still makes a whining sound. I also adjusted the tension on the p/s and gave it a little more slack, that helped a little easing the whining, but it still persist. Could my problem be a bad pulley or bent shaft?
AnswerIt could indeed be a bad pulley or bent shaft. You'll need to do some investigating to find out the source of the noise.
First, spray just a little WD-40 or similar lubricant on the belts while the car is running. If this causes the noise to change, it's coming from the belts themselves. In this case, you can try playing with the belt tensions some more to see if you can make the noise go away. But as long as the belts are in good condition, the noise is not an indicator that there's a problem. It's just an annoyance.
If the noise doesn't change, you'll need to isolate the cause. To do this, take a long screwdriver and probe around the various drive items and the idler and tensioner pulleys, if you have them. While the screwdriver is on a component, place your ear on the other end of the screwdriver. The closer you are to the source of the noise, the louder and clearer you'll be able to hear it through the screwdriver.
