Water pump bearing can go out without notice. It may squeak one day and the next day seized. Then, you will be in a whole lot of trouble. At 153K miles, those are a lot of miles on water pump. As you replace the pump, consider replacing the thermostat at the same time. They are next to one another.
You have a timing chain, not belt. But your water pump is driven off your power steering serpentine belt, not the timing chain. You may want to look at the condition of your belts (both of them) and decide if they are due for replacement.
Friday, March 6th, 2009 AT 12:38 AM