i just purchased a 1995 contour se v6 with 51000 miles on it.bought a warranty covering major engine,trans for 3 yrs.water pump will be 50% covered.im seeing alot of horror stories about the pump failures.when do they start exploding?60000,70000 etc.really cant afford to get it done now.is this something i can put off awhile and hope it happens during warranty,or should i change it asap?thanks