Ok, so about two weeks ago, my serpentine belt came off while I was driving home. So far, I have checked the pulley alignments, and replaced the belt tensioner. Still, the belt keeps coming off. After all that, I finally checked my water pump pulley and it wobbles when I touch it. Would that be a pulley issue or the entire water pump assembly?
My car has 165000 miles.
My car has an automatic transmission.
This is typically a sign that a bearing has failed inside the water pump. When the bearing fails it allows the shaft that drives the pulley to move around, and is probably what is causing the belt to be thrown. It will require a new water pump to be installed. If this repair is something that you will need a hand with, contact a certified mechanic, like the mobile mechanics available at YourMechanic.com.