How long would you guys say a water pump would last for on the z20let?? Ive always thought when you change a cambelt you do the water pump. Only reason why i ask is ive been looking through the history invoices on my car and it had its first cambelt change at 39,508 miles in sep 2004 along with the water pump being changed. Then it had a second cambelt change at 90,235 miles in oct 2008 with no water pump. The current mileage now is 104,000 miles. Anybody have any thoughts on this??