Wife's navigator water pump failed on the way to taking the kids to school yesterday. I was able to swap in a pump from O'Reilly's and all seems fine. The major leak occurred around the impeller seal. The oem impeller was plastic but the O'Reilly's Chinese part was aluminum... Hated using a Chinese part on a job that took me about three hours to do but was surprised to see the O'Reilly's part to be similar or better quality than OEM. At 85k miles I'm disappointed that this is even a thing that could fail....

Never been a fan of metal impellers. They didn't have any plastic impeller WPs?

JamesPShelley said:

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Never been a fan of metal impellers. They didn't have any plastic impeller WPs?

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They didn't. But curious why you would prefer a plastic impeller over and aluminum one?

3rdgenAg2010 said:

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JamesPShelley said:

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Never been a fan of metal impellers. They didn't have any plastic impeller WPs?

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They didn't. But curious why you would prefer a plastic impeller over and aluminum one?

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This is what I ran across on my 986 forum. The poster is one who hardly ever never is incorrect. He said:

"When the bearings go bad in these water pumps, and they all will go bad regardless of who makes the pump, the shaft starts to move side to side resulting in the impeller hitting the front of the engine case. With a composite impeller, the impeller breaks up, which can cause cooling system blockage if you don't flush all the bits out. If the impeller is metal, it starts machining away the engine case, which also fills the cooling system with fine metal which is a royal pain to get out, but it also permanently enlarges the clearance between the pump impeller and engine case, resulting in permanently reduced coolant flow regardless of which type of pump is used, and ongoing cooling issues."

I have worked on a fair bit of vehicles/tractors and I have done a few water pumps. I've never to date seen a water pump fail so bad metal and plastic plugged a system and that includes trucks that are over 50 years old. I don't know what the heck people are doing with their cooling systems, but I have no preference to metal or plastic. Mine have all weeped coolant way before there was any noticeable slop on bearings. The only thing I do is try to make sure I use OEM parts if I can at all help it but I have used oreilly aftermarket and it hasn't mattered. My oreilly pumps have lasted 100,000 miles.