It could be a few things:
*your serpentine belt could be loose or glazed (possibly due to bad tensioner); at 95,000 miles replacing it regardless may not be a bad idea anyway. A belt that looks good on the outside could be worn inside.
Important: when you replace your serpentine belt, scrub ALL the pulleys with scotch brite/wire brush/etc, then spray some brake cleaner on them. That will get rid of the glaze on each pulley. If you don't, the pulleys will glaze the new belt quickly (ruin it) and the noise will come back.
*Your serpentine belt tensioner may be on its way out (with engine on, make sure the tensioner doesn't move up and down too much. If it does replace it).
*One of the pulleys driven by the belt could be misaligned (check with a straight edge).
Here are two quick tests to determine if misalignment is your problem:
- Using a spray bottle filled with water, mist the belt lightly. If the noise level recedes for several seconds, then returns louder, a misalignment problem is likely. If the noise immediately increases after the belt is sprayed, slipping is likely.
- Remove the belt and re-install it so that the belt runs in the opposite direction (flip the belt around). If the noise goes away or diminishes a lot, misalignment is likely your problem. If the noise remains unchanged, the problem is not likely related to drive alignment.
*Bad pulley bearing. You replaced the power steering pump, and alternator; that leaves the water pump, and the compressor as potential culprits. Remove the belt and try to pull the pulleys in and out; they shouldn't move. If you feel some looseness, the bearing is no good.
Hope this helps
Monday, November 13th, 2017 AT 8:45 PM