Use gt3 water pump with metal impeller?

[mikesz]

That is why I work on my 99 Boxster. When I pay someone to do something I expect them to know more than me and do a better job. Not usually the case.

[Gelbster]

This subject comes up often but seldom are there detailed explanations of why metal/plastic is the best choice.The threads deteriorate just like the oil chioice threads.Not helpful. I have the curse of an inquiring mind so here are a few details that others may add to/correct.
1.The aluminum blades will only score/abrade the w/p housing if you neglect a worn bearing.
2.The plastic blades will also mark the housing if a wobbly bearing is neglected. More serious - the plastic blades can disintegrate (but why-age/heat??). You will need to dismantle the entire engine to retrieve all the little pieces .Why? Because they block the coolant passages & then......Just done that job!
So pick your poison.
Best suggestion whichever you choose - is watch for coolant leaks from the w/p or noises and replace the pump immediately or 60k miles ?

[Myoung73]

Originally Posted by Gelbster

This subject comes up often but seldom are there detailed explanations of why metal/plastic is the best choice.The threads deteriorate just like the oil chioice threads.Not helpful. I have the curse of an inquiring mind so here are a few details that others may add to/correct.
1.The aluminum blades will only score/abrade the w/p housing if you neglect a worn bearing.
2.The plastic blades will also mark the housing if a wobbly bearing is neglected. More serious - the plastic blades can disintegrate (but why-age/heat??). You will need to dismantle the entire engine to retrieve all the little pieces .Why? Because they block the coolant passages & then......Just done that job!
So pick your poison.
Best suggestion whichever you choose - is watch for coolant leaks from the w/p or noises and replace the pump immediately or 60k miles ?

Great info. And the first post to suggest using the metal impeller pump might not be a horrible idea... I agree with the overall idea of keeping an eye on it and not letting it get to be an issue either way...

[JFP in PA]

Originally Posted by Myoung73

Great info. And the first post to suggest using the metal impeller pump might not be a horrible idea... I agree with the overall idea of keeping an eye on it and not letting it get to be an issue either way...

Actually, it is a horrible idea. A metal impeller pump can do serious and permanent damage to the engine cases, filling the entire cooling system with fine metal that is difficult to remove without taking the engine apart, and even then will result in reduced cooling capabilities because the space between the pump impeller and the cases is now too large to facilitate proper coolant circulation. Bad idea all around.

[Gelbster]

I always defer to experienced advice. Plastic it is !