Battery Guy

No - it was a Porsche factory water pump. We are not sure if it was the original pump or a replacement done in the past. The car has 75,000 miles on it, so if it was the original it would have been due. Wish I had taken a picture - the impeller was the plastic type - some of the vanes were worn smaller than the others. No sign of fracture.

Battery Guy

[QUOTE=85eurocarrera;15955159]The only fix is to replace the water pump.
Daryll

wildbilly32

I think Pt3 was questioning that if the "bore the impeller runs in is out of round" that would be a big issue as that cavity is in the actual engine block and if damaged can render the block unusable. I'm hoping that was not the issue causing the coolant leak.

Battery Guy

OK, sorry - I did misunderstand the question. No, the engine block is fine - the bore that I was referring to was the water pump casting itself. You could see where the impeller shaft bore in the pump was worn. I am certainly no pump expert, but I would say that the wear was expected end of life for a spinning part running in a casting. The wear on the impeller blades was interesting to me. I need to run by the shop tomorrow - if they have not tossed the old pump I will take a picture.
Thanks!
Daryll

wildbilly32

Aha! Yes that is how they fail due to age/wear and cause one heck of a water leak as you found out. Some abrasive wear on impeller blades from the compromised shaft "bearing" is not unexpected to me. That's the reason to not use the metal impeller as it will machine away inside the water cavity and possibly destroy the engine block.

Porschetech3

Here is a pic of the bore where the impeller impacts the block when the bearings fail ,it breaks the blades of the plastic impeller, and if it has the metal impeller, gouges in the block. Neither is a good scenario..

When the plastic blades break off the impeller, they go into the engine. You should find out how much of the blades are missing. There is really nothing that can be done now, but could be helpfull in diagnosing a problem down the road if the blades pieces get stuck in the wrong place.

I just had this same problem on my sons Boxster, that's when I decided to make the screens in the picture . Of course it was too late, but better late than never, and may be useful down the road,or if another pump fails.

Battery Guy

Was back at the shop today for a top-off of coolant (it burped over the weekend) and the pump was already gone. But I did see it - none of the impeller blades were broken off - they just showed wear. So hopefully any bits that are circulating in the cooling system are tiny particles. It appears that I may have caught this in time before anything worse happened, beyond having to replace the pump.
Daryll