Engine Block damage due to water pump impeller blades

Hello everyone, I�m new here. My newly purchased 2004 Boxster began leaking coolant soon after a trip from Dallas to San Antonio, Texas. I turned the car off and had it towed to a European car specialist. Today they finally called and told me that after removing the water pump they found that the engine block is worn around the water pump impeller housing due to the impellers rubbing against it . They continued on to say that the entire engine block would have to be replaced and obviously not cheap. But is this really the only viable option? Any help or input would be greatly appreciated

U could just clean it up and run it. The pumps r sized too big any ways and would doubt there would be a flow issue. U could also epoxy or alumaweld and rework the surface. The problem is there is a risk of it coming loose and cloging a passage. this is why the compsite blade waterpump should only be used on these blocks.

^^^All of the above^^^. I would think that a �weld and machine� type of repair would have little chance of coming loose (unlike epoxy� I wouldn�t trust that for a second) and would be good for the life of the engine. The main caveat being finding a shop that hopefully has some experience with similar type repairs (ideally this exact repair). Good luck, and whatever you do don�t replace the water pump with a metal impeller� Good Luck

There is a guy that makes a repair kit for 928's 928 Block Damaged by Water Pump Repair - Rennlist - Porsche Discussion Forums I have not been able to find equivalent for M96

Is the wear directly causing coolant to leak? While not ideal, I would think you would, at the most, lose some pressure in the system since the gouge is contained inside the passage and did not breach the gasket. Maybe I'm not analyzing it correctly?

So much for the impeller shaft being designed to shear. I'm glad I went with the Perberg/composite when I did mine. OP - do you have a pic of the pump/blades?

My question to everyone is would you rather have this happen or small broken bits of impeller throughout the cooling passages?

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Niether...

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I�ve replaced 3 water pumps in the past 10 years, in 3 different Porsches I�ve owned. the first was 2001 Boxster S. The original pump failed at 74K miles. the second one was on my 99 Boxster base. Failed at 165k miles. I assume it was privately replaced, but the one I took out was OEM. the 3rd one is my 2002 C2 that is still on the lift. Pump failed at 58k miles. Original pump. all 3 came out with perfectly good plastic impeller, and no damage to the block. so I�m sticking with OEM (Pierburd) plastic.

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first time I hear about that. from what I know the baring seal is designed to leak when the bearing is going out, long before the bearing completely fails. I just removed the pump in my car with 0 play on the shaft and impeller (that looks brand new). The bearing sounded bad though.

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Bits of the engine block, or bits of the impeller -- is there a difference of any consequence?

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The correct way would be to replace the block, but it would cost 3x what the car is worth. I would replace it and drive it and watch the actual engine temps with an Ultragauge plugged into your obd2 port. Since the stock gauge is useless above 180 this will give you a real life understanding of how hot it�s running. Don�t be a bit surprised if you see temps above 190 and the factory gauge is still at 180 though.

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I don�t, I plan on seeing the damage in person I�ll take some pictures when I go to the shop.

�The correct way would be to replace the block, but it would cost 3x what the car is worth.� ^^^ Not really� this is a Boxster engine. They can be gotten pretty readily for $3-6k. Find a good used one and flip all the ancillaries (or not if they�re in good shape/better than what you�ve already got)�

Looks like the consensus so far is replace and monitor . Which sems prudent .Don't know anything about the shop that has it but they might see this as a margin improvement opportunity .

This is why you replace the water pump on a regular interval before **** happens. 60K miles is my interval.

This is from a one-owner high mileage 996 regularly serviced by Porsche dealerships and only genuine OEM pumps with plastic impellers were used. What are your thoughts on this?

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Plastic bits can be flushed out of the cooling system, damaged blocks create boat anchors. Porsche used composite impellers for a reason....................

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i would say that the composite wore away the machined surface but in no way ate into the block like the original post.

Wouldn't there be a lot of squealing noise when the impeller of any material rubs up against the block to the point of wearing out the block? And wouldn't an aware owner know and hear this noise and further investigate?

Guessing it would sound more like a scratching sound that would be hard to hear over everything else. But if one were to periodically check by spinning the pump by hand, they might feel or hear it. But who does that? Only paranoid P-car owners� I agree you should be able to fix the current engine with the right approach.

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Good and used are the key words, pick one or the other. You might get both, one, or neither.

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Put a new composite impeller water pump in it and drive the tar out of it.

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Yea, I agree. The rubbed area does not down this block unlike what metal impellers would do. But you can see how even plastic impellers can somewhat buff out the original machined area.

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I guess DSC800 is mixing up the water and oil pump (drive) in this respect. The oil pump drive is said (not by me, mind) to be designed to give (by failing) before other damage can be done by a stuck oil pump.

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Maybe, but the first thing I thought of was having read somewhere the aluminum blade would cause the shaft to shear before chewing the block. This was back a year and half when I did my pump and deciding which to go with (pierberg composite). I just did a quick search here of "shear" and nothing came up related to the water pump, so scratch that.