i had a bad squeek from under the hood when it is cold or at different times. i was able to track down the bad part the pulleys. here are the stock plastic pulleys. there is one below and one to the right of the ac compressor. here is a better view of them here are the replacement pulleys. i go the steel upgrades for a couple dollars more. these were NAPA part number 38001 and 38006. i removed the serp belt and set aside. i used a 15mm wrench to remove the idler pulley. you can see the old and new pulley.