I have to disagree with those urging oem replacement.
While I usually always go oem, the waterpump is simply inferior to several of the remans or aftermarket ones out there using a metal impeller instead of the oem plastic one.
Not only is coolant flow reduced and debris forced through the system (possibly clogging it) as the impeller degrades, but it also throws the shaft out of balance shortening the life of the bearing, seal, and the pump itself.
The pumps with metal impellers don't cost any more, in fact, they're usually less than oem.
