GEBA pump with metal impeller
 

Well the new GEBA pumps from Germany are being shipped with metal impellers :)
I think thats cool because the VW Jetta/Golf ones constantly break and all the ones that get replaced with the revised metal impellers rarely have any issues. Anyhow the pump comes with the gasket and looks good :)
Thought I'd share the pics (Pump rev 01/13)

This one is going into my S as soon as I wake it up from its winter nap :)

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Nice, I have to do the same thing! I have not seen this pump before. How are the bearings in it? Are they more substantial than the OEM ones?? Maybe we can go halves on a pressure bleeder

Thats an excellent "milling machine" to destroy your crankcase when the bearing fails. People think they are "out smarting" the water pump issues by using these metal impeller equipped pumps, then they learn the hardest lesson possible.

Why in the world would you want a metal impeller? WPs fail because the center bearing fails. When it fails, the impellers hit the engine case. If the impellers are metal, they will chew through the case and ruin the motor. If the impellers are plastic, they break off and save the case. What proof do you have that metal impellers make a better WP?

If that bearing goes and that shaft angles enough to make the impeller touch the case, then the belt and the pump will be making noise long before. Anyhow I dont mean to get into any arguments over this but the GEBA pumps are not 'cheap knockoffs' and I put a lot of trust into their products; GEBA pumps are used in a lot of high end applications and I'm sure their product is good.

Not starting a debate here, I just wanted to show the new pump.
Over and out...

Not trying to add to the debate, but the plastic impellers break even when the bearings are still fine and there is no shaft wobble. The risks of each type are well documented, so we make our choices and take those risks that come with what ever pump you choose. It's your car to do whatever you want to do to it.
There are plenty of used engines around to replace whatever type of failure you may experience, whether it is a breached crankcase or a cracked head.
The joys of Boxster ownership live on.

This...

I've been stranded twice by plastic WP impellers that split in half. I've had only one metal pump fail, which amounted to a minor leak long before catastrophic failure was likely. I'm sure others have legitimate reasons for their feelings on the subject, but my experience is that the "metal mill" scenario is one that I've only heard substantiated second hand. Lots of grim warnings about the risks, but no pics or rist hand accounts. Is there any one out there that has pics of their damaged block from a metal impeller??

shadrach74 - there seem to be pro's and con's to each scenario when you look at failures and how they happen etc. Since GEBA just started running this pump since late last year, I thought i'd send them a message to see what they had to say about this 'new' metal impeller setup and how it fairs against the dreaded 'engine case destroyer scenario'. (I like their products because they make awesome pumps for VW and BMW) anyhow... I got a very quick and kind reply from the production manager in Germany.... (which I will translate to short here)
"We started production of the new pump 15007 at the end of 2012 and decided to utilize a metal Impeller because of the known Problems with the plastic ones. We also decided to utilize for these pumps the original bearing which Porsche is using for their production series which features an added Roller Bearing design which will reduce radial and axial play to a minimum." Also the distance between the pulley and Pump housing are extremely small, so if bearing failure would occur the Impeller could not move significantly into any direction"
Looking at this new pump, I like it; its not cheap, but equally priced to the LASO pump which seem to have its own set of issues at times.
Anyhow, I like trying new things especially when its new and revised - technically it should be better :)

Good for you Heiko. It is nice to see guys who are willing to challenge the norm. I too was thinking of a quality pump with metal impeller for the next go. Please tell us where you sourced the pump and what it cost to purchase. I know these things often have higher prices outside the USA.

We bring them in through 'Auto Camping' but I think WorldPAC carries them as well... (haven't checked with them yet) We sell them out of the shop for $329.00 + tax... I know the dollar is basically par but I wouldn't be surprised if you can buy it cheaper over the counter in the US than we can wholesale up here... seems to be the way it goes :(

The person who made those statements has obviously never touched an M96 engine. Typical.

Jake, no offense but that's like saying 'no one' will ever be able to make a metal impeller pump that works because you've written them off due to bad experiences... personally I like to think positive and give folks the benefit of doubt especially when it comes to new and improved products.

We have had three cars in the shop that had the engine cases ruined by metal impellers on aftermarket pumps that had to have replacement engines. In addition, we have had others where the engine cases were torn up, but still intact enough to be used, although they needed extensive work to clean the fine metal dust out of the cooling systems before they could go into service. And in each case, they suffered overheating issues because the clearance between the rear of the impeller and the engine cases was now large enough to reduce the pump's ability to move coolant.

Listen to Jake; he is spot on with this problem.............

Note: WHEN it fails...! Not "if" and regardless if you maintain your car, but WHEN it fails, you're done.

Which was then followed by this classy retort...

Wow. So the take away from all this is you can't use a metal impeller because it will almost immediately come alive, devourer your block, and when it's done come after you and your family.

So in summary, water pump with metal impeller = :troll:

And you can't use a pump with a plastic impeller because you won't get around the block without it shredding into plastic confetti requiring a complete tear down of the entire engine for cleaning.

water pump with plastic impeller = :barf:M96

What I'm taking from all this is that Porsche can't even design and build something as simple as a cooling system/water pump that doesn't totally suck. Why am I not surprised... (IMS, dropped sleeves, etc.). Seriously, it's like trying to work with those as$ clowns over at Chrysler all over again - and they were a joke.

Why is every failure apparently catastrophic with this company?

Hey Porsche, if the cooling system was a little too tough to handle, why don't you try an engineering task just a little simpler. You know, to get some points on the board and hopefully build some successful momentum...

Here's a wet paper bag.

In my mind, the solution here is remove Porsche engineering from the equation all together.

http://986forum.com/forums/performance-technical-chat/43501-electric-water-pump-electric-ps-pump.html

The rear of the water pump housing in the front of the engine case. The impeller blade has to sit very close to it (perhaps a couple thousands of an inch) in order for the pump to actually move the coolant. Eventually, all water pump bearings wear, and the shaft starts to wobble a bit, when that happens, the gap between the water pump impeller and the cases starts to get very tight and eventually the impeller makes contact (which is also why when a composite impeller wears, it wears at the outer edge). When it does this, there is often no noise as the sound is dampened by both being enclosed and submerged in coolant. So you have no warning anything bad is happening until you suddenly find an intermix problem.

Porsche is not the only one using composite impeller pumps because of the proximity to the alloy engine housing. A metal impeller is harder than the housing, so the housing will lose the argument. A composite impeller is softer than the housing, so the opposite happens.

Automotive engine design is always a matter of trade-offs. With a metal impeller, the risks are simply higher.

Jake has been saying beware of the metal impellers for years. So have others whose experiences with the insides of M96 engines is measured in multi hundreds. So who are we to believe, the experienced or the theorizers?

As for the mousetrapness of his "The Solution", recall that the phrase "better mousetrap" may just apply. We probably won't be able to know for another 10 years for sure and even then no one will keep statistics. Only forums that support ancient antique-license cars will come to a consensus.

Maybe all we can tell is it makes sense. More stability, larger bearing surface, used in other Porsche vehicles, lubed with just-filtered oil.

There are those who said the IMS wasn't a big problem, the law suite Porsche is settling says they finally agreed with Jake that, for some years, it really was a BFD.

I've know this bearing and its lubrication system was in development for several years and knew when it was first installed on high HP engines developed in his shop. Several others have tried to productize the same sort of idea (pressure oiled) some with flaws in their design, some without success and some with just a simple failure to pursue the idea once they realized the costs in development and the challenges of support. He expanded the idea of how to lube for longer life with the insight that it was a better bearing that also was needed. Good for him and for all those who try to come up with solutions for us.

How many people do you know are dissatisfied with an engine he built for them? How many product developers come right out and tell you the product isn't for everyone and here are those it isn't right for? Maybe the guy just really has a good reputation.

I've gone through the patent process, it is long, expensive and arduous. Try 2 years and a couple of hundred thousand lawyer dollars and that was with me basically answering all the patent examiners letters and doing all the engineering documentation. (I won.)

And as soon as he does put the details out in public, others will try to sell a product they claim is similar without incurring those expenses/delays. If he comes across as frustrated sometimes, he is entitled.

I def agree that all automotive engineering and manufacturing is really no more than a serious of compromises. I used to think there were two ways to approach those compromises. 1) By making intelligent, data driven decisions, or 2) The Chrysler way. I'm becoming more and more convinced the interns over at Porsche that designed the M96 decided to go with#2.

With that said, thank you for making a very informative case supporting your opinion of the superiority of plastic impellers. And thank you for the professionalism of your reply. Maybe some of the other pro plastic impeller guys can follow your example.

Congrats on having the tenacity and determination to successfully navigate through the patent process. As a guy who's been there myself, that alone earns you my respect.

However, being relatively new to Porsches and certainly new to this forum, with its long running debates, social hierarchies, and thinly veiled politics, who does and who does not deserve the right to entitlements is certainly subjective. I certainly appreciate accomplishments, experience, knowledge, and intelligence but I also appreciate patience, long suffering, and humility. I'm just saying.. ;)