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Missing water pump blades

Old 06-25-2019, 06:27 PM
  #16  
Chris(MA)
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I'd be really curious to see a teardown of the bearing(s) in that water pump, it would destroy it, but its done anyway. It failed really soon, a bit concerning for the rest of us..
Old 06-25-2019, 06:32 PM
  #17  
Woodman71
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Seems Jake tried making screens for this about 14 years ago.

https://rennlist.com/forums/996-foru...with-pics.html

"I did that at least a decade ago.. The issue with it, is it blocks ALL the coolant flow right out of the pump, and you have no idea that you've had a failure. Why is that bad? Because without a flow of coolant, there's nothing to get the temperature up at the coolant temp sender, which is located OUTSIDE the engine, in the front coolant console.

That means you bake the engine, but you never even know it, because the gauge says the engine is normal temp. Lots of good ideas, end up being bad ideas when the whole cause/ effect is looked at in a big picture."
Old 06-25-2019, 06:35 PM
  #18  
Porschetech3
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Originally Posted by Chris(MA)
I'd be really curious to see a teardown of the bearing(s) in that water pump, it would destroy it, but its done anyway. It failed really soon, a bit concerning for the rest of us..
Yea, I have intended to bust it apart and take pictures of the bearings to show the forum. But haven't gotten around to it yet, it's only been a week or so since I have done this. The last count I had the 996/986 has 18 "sealed deep grove ball bearings" (besides the infamous IMSB)....
Old 06-25-2019, 07:08 PM
  #19  
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Originally Posted by Woodman71
Seems Jake tried making screens for this about 14 years ago.

https://rennlist.com/forums/996-foru...with-pics.html

"I did that at least a decade ago.. The issue with it, is it blocks ALL the coolant flow right out of the pump, and you have no idea that you've had a failure. Why is that bad? Because without a flow of coolant, there's nothing to get the temperature up at the coolant temp sender, which is located OUTSIDE the engine, in the front coolant console.

That means you bake the engine, but you never even know it, because the gauge says the engine is normal temp. Lots of good ideas, end up being bad ideas when the whole cause/ effect is looked at in a big picture."
Well, I'm glad Jake has thought about this catch screen, but he doesn't sell parts/mods anyway, so they would just be used on his motors, or sold through LNE, and there is really no money to be made on them.

But I dissagree that it's a bad idea. I don't think enough debris can be created by the broken blades to TOTALLY BLOCK the coolant flow in that large area. If the bearings start to fail, I think the water pump will leak before ALL the blades are broken off or enough to TOTALLY block the coolant flow of even the smaller passages( and flash the low coolant light.). Plus I have oil temp gauges and I think the between oil temp and coolant temp, even with reduced flow, I will know when the engine starts to overheat..Plus there is some movement of coolant even without a water pump through "convection" .The first IC engines had no water pump. The water was circulated only through the principals of hot water expands and rises, and displaces the colder water. I have installed "block heaters" on Porsches for customers who were headed up North, and with a block heater, the temperature guage would rise as the water warmed with no circulation from the water pump.I will NOT be removing the heads or disassembling the engine to remove water pump blades..

Last edited by Porschetech3; 06-25-2019 at 10:56 PM.
Old 06-28-2019, 03:09 AM
  #20  
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Default Deep grove ball bearing + roller bearing

Originally Posted by Chris(MA)
I'd be really curious to see a teardown of the bearing(s) in that water pump, it would destroy it, but its done anyway. It failed really soon, a bit concerning for the rest of us..
Found time to bust apart the water pump, and to my surprise there is a deep grove ball bearing AND a roller bearing in there. I was expecting to see two ball bearings, but the ball bearing is to the pulley side of the shaft, and the roller bearing is to the impeller side of the shaft. You can see in the pictures the outer race/sleeve has fatigue pits in it where the ball bearing runs. The outer race for the rollers looks fine but the rollers themselves don't.

Shaft/outer race-sleeve/rollers and *****

closer view of damaged rollers and *****, they flew everywhere when I busted it apart, I'll be finding them for a year..

outer race deep grove ball bearing side, you can see the fatigue pitting

outer race roller bearing side, has damage at the inner and outer running edges

shaft: the brass at the top is the center of the impeller(plastic impeller broken off, then seal area, then roller inner race, then the groove for the ball bearings

OEM part number
Old 06-28-2019, 03:24 AM
  #21  
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There was a big thick seal behind the impeller, but there was no lubricate that I could see in the bearings, there was also a lot of surface rust which should never be in there.I'm thinking there were never any lube in the bearings, or very little.

stacked a few roller back in

couldn't get any of the ball bearings back in

the heart of the water pump
Old 06-28-2019, 07:43 AM
  #22  
dan_189
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FYI just happened to be in PET2 and looked the water pump up - they are up to revision 57 (supersession: 51, 54, 55, 56, 57) with the latest part number:

996 106 011 57

Wonder what the differences have been...
Old 06-28-2019, 03:40 PM
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Good job! That mesh will have some restriction to the coolant system but hopefully not enough to make a difference.
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Old 06-28-2019, 03:51 PM
  #24  
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Originally Posted by dan_189
FYI just happened to be in PET2 and looked the water pump up - they are up to revision 57 (supersession: 51, 54, 55, 56, 57) with the latest part number:

996 106 011 57

Wonder what the differences have been...
I honestly don't know what changed are on the higher revisions,we can only hope they are a better pump, not just a different supplier.
Old 06-28-2019, 04:05 PM
  #25  
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The Pierburg water pump I installed has fins that are light brown. I think the original one I pulled out had the same fins but I can't be certain. I was under the impression that Pierburg was the OEM supplier. I have another replacement on hand for the future and it has the same fins, but it doesn't have a Porsche part number on it, just their own.
Old 06-28-2019, 05:44 PM
  #26  
jumpy chunky
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Originally Posted by Porschetech3
I honestly don't know what changed are on the higher revisions,we can only hope they are a better pump, not just a different supplier.
I was wondering not just about pump quality, but the tension on the serpentine belt. Seems pretty darn snug to me. I replaced mine with the Continental version and hope it is the correct length. Can't deflect with my thumb at the pump.
Is there a value for tension? If so is there a tool?
Old 06-28-2019, 06:31 PM
  #27  
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Originally Posted by Imo000
Good job! That mesh will have some restriction to the coolant system but hopefully not enough to make a difference.
Thankx !! I have been driving it pretty much every day, no difference seen..
Old 06-28-2019, 06:37 PM
  #28  
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Originally Posted by jumpy chunky
I was wondering not just about pump quality, but the tension on the serpentine belt. Seems pretty darn snug to me. I replaced mine with the Continental version and hope it is the correct length. Can't deflect with my thumb at the pump.
Is there a value for tension? If so is there a tool?
There is no data on the tension. It is controlled by the spring and belt length. I'm sure you could use a standard belt tension gauge, and get a value off a new serpentine system with new spring and correct belt to get a value, then use that to value to evaluate used systems, but I don't know of anyone who has went to that much trouble, even the Factory.
Old 06-28-2019, 11:31 PM
  #29  
dan_189
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Originally Posted by Porschetech3
I honestly don't know what changed are on the higher revisions,we can only hope they are a better pump, not just a different supplier.
That's quite interesting actually, so even with a supplier change there is a revision?
Old 06-29-2019, 12:25 AM
  #30  
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Originally Posted by dan_189
That's quite interesting actually, so even with a supplier change there is a revision?
I have been told that , but haven't seen it "officially" in print from Porsche, so I take it with a grain of salt. What's also interesting is I was told revisions always start with 00, why on earth would Porsche need/ want to revise an M96 water pump 57 times?

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