56 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHWater Pump
Leading reported evidence
Replace belt as it was cracking
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
I also changed the belt as it was cracking already.
Leading evidence: 'Replace belt as it was cracking' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'biggest tip' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check /' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I haven't had a water pump failure but I had mine replaced just to be on the safe side.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Are you also planning to check/replace: serpentine belt, t-stat, lines/hoses, tank and cap?
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Be sure to check the fins when you take out your old to ensure there are no pieces floating around in the system.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
56 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T163944Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Hey fellas
I was planning on doing the water pump this summer, but it actually took a crap on the way to Vegas this weekend. Im probably going to start taking it apart slowly throughout the next few days taking my time doing it in the evening after work. I was looking around to which one to order and there seems to be a lot of aftermarket ones ranging from $75 all the way to about $300 (same price as OE). Most likely I will go with the OE because on a crucial part like that I don't like dicking around just to save a few bucks. But just wondering if anybody has used any aftermarket ones and if they were any better then the OE?
Thanks bud
I have read through the threads on metal impellers. I wouldn't go that route, however there are quite a few aftermarket ones with composite impeller.
I have read a post or two about aftermarket impellers coming apart - now, that's probably just an instance of one bad pump out of many, but given what a PITA the thing is to R&R, might as well use the OE.
yup - just did mine and considering how "fun" it was I want this one to last as long as possible. Went with genuin Porsche instead of anything aftermarket.
When you say took a crap, what actually happened? Is it just leaking or was it a complete failure? Be sure to check the fins when you take out your old to ensure there are no pieces floating around in the system. you will want to get all of those out.
One more vote for an OEM pump. Are you also planning to check/replace: serpentine belt, t-stat, lines/hoses, tank and cap?
P.S. Please do not ask if you should go with a low temp t-stat or not
Thanks for all the input guys
It wasn't a complete failure, just a steady leak. I pulled over right away as soon as I got the low coolant light. I will definitely check the fins (fingers crossed) as I would hate to try to track them down if they go missing.
I will do the serpentine belt and check all the hoses for any aging and crack. But I will leave the rest untouched. Maybe and that's a big maybe ill do the t-stat.
Make sure that it is the pump that is actually at fault. The system could be loosing coolant somewhere other than the pump. If you are sure, then make sure you mark up where the 7 pump holding screws came from as two of them are longer than the other 5 and need to go back in the same place. A fiddly DIY but very dooable.
Just had water pump and thermostat done by my shop. That was a quick $800.
Ugly time of year to try and get more wrench-capable friends to assist on a DIY job and I didn't want to leave it dripping.
Ouch.
Yeah i hear you Ralph. For the past 2 days all i have done is just put the rear of the car on ramps. Everyday i get home from the office i go and stare at it for about 10 mins. trying to convince myself to start taking it apart. Im a hard guy to convince so i just walk back to the house and tell myself there is always tomorrow.
I would think a metal impeller would be better as cars before they started using composite impellers never had problem except leaks, bearing failure, etc...
I'm doing a rebuild on a 996tt motor and went with a Geba w/ metal impeller and it's made in Germany too.
I have the OEM Pierburg in stock too that I can ship anywhere in the lower US for $245.00 out the door. No sales tax unless you're in MO. Like mharrison says above, Pierburg is the exact same pump just not in the Porsche box.
-Jason
Finished doing the pump today. I went with Pierburg. Blades on the old pump were all there so i lucked out on that part. I also changed the belt as it was cracking already. All the rest looked fine.
BTERRY thanks for your advice on pulling the pump from up top. I actually removed the two belt tensioners and wiggled it out. Put the new one in the same way. Next time im in SD im calling you to grab a beer.
I basically followed the
Pelican Parts Tech Article
or 101 Projects for your 996. (They are exactly the same. Same pictures and everything.)
Even if you get an aftermarket pump, get a Porsche brand metal gasket. My fiber gasket was seeping a bit and that's why I had to do it twice! Doing it again immediately after doing it was REALLY quick. I remembered all the quirks, odd angles needed, etc. It will honestly probably take me closer to an hour/hour and a half next time.
One big suggestion I would make is to replace the thermostat (and gasket). Take the thermostat housing off before pulling the water pump and put it back on after replacing the water pump. This gives you the room to easily get the pump out (and back in) from the bottom. I tried removing idler pulleys and such to get it out the top. It just was not happening. I don't know why that works for some, but didn't for me.
Also loosen the hard line that runs around the oil pan across the top of the thermostat. This gives you a bit more working room. Here's a pic of the line I'm talking about. It is attached with 3x10mm bolts that are very easy to reach.
You can save some money by using Pentosin SF (available at O'reilly Auto Parts) rather than buying the pricey Porsche coolant from the dealer.
I think I add this to every water pump thread - but it's worth it. Remove the idler pulley that's just above the pump. This allows you to lift the pump up and out and drop the new one down in place rather than trying to get it out from below. I spent an hour or two trying to get the pump out from below - once I removed the pulley, it was stupidly easy to pull the old one out and drop the new one in.
*edit* Oops, I see bterry beat me to it.
For whatever reason, this didn't do anything for mine. The water hose fitting was hitting the rear mounting plate before the impeller cleared the block.
Maybe the geometry is a little different for every car. I could never get the pump out the bottom due to the hard lines, even after removing all of the bolts holding the hard line in place. It slipped up and out with almost no effort...
I still have the Pierburg's for $245.00 with free shipping in the lower 48 US and I'll include the gasket with that price. Contact me to purchase.
And thank you to the 2 Rennlister's that purchased one over the weekend from me.
-Jason
Having seen a motor lost due to a failed Porsche water pump with a composite impeller, I'm quite interested in the metal impeller.
In this case, the bearing failed but the pump never leaked a drop. Nor was there any noise until the damage was done. The composite impeller got into the block and shed pieces throughout the coolant system. This debris lodged in the oil cooler (water/oil heat exchanger) and in the little nooks and crannies of the heads.
The Porsche 996 gurus at PCA said the correct technique to remove all this debris. "Disassemble engine". WTF,O?
My feeling is that one has at least a fighting chance of hearing a metal impeller contact the block. If the referenced part uses metal 'fins' rather than a cast metal impeller, I don't foresee any significant block damage as the fins would simply bend away from the block.
What do these pumps look like, Jason?
And for the naysayers, what are the perceived disadvantages of a metal impeller?
The part itself is pretty cheap, and they usually last about ~60k. Im sure there are cases where someone had it fail prematurely, but thats a very small chance. So i would just stick with OE and do it as a PM every 50-60k miles just to be on the safe side and not risk any metal impeller damage or composite impellers in the engine.
Composite impeller debris - just rebuilding an M96. Impeller debris in the oil cooler and heads.
I am sure the mechanic who replaced the old water pump would have noticed the missing parts from the old impeller. So when the Mechanic told the P.O. ,he said what? Anyway they just slapped in the new pump,sold the car and left the consequences to the next owner(me).
I like the theory of using metal impellers because of the noise a failing pump would make. It sounds silly until you remove an old composite pump and notice there are impeller pieces missing -where are they?
Anyone instal an in-line screen to 'catch ' the broken pieces before they scatter into the cooling system ?
Larry Hughes,
I prefer the metal impellers as I have never seen a failed water pump due to the metal impeller coming apart and usually those fail as the bearing craps out or they develop a leak. I have seen a few pumps fail with the composite impellers that the bearing is still good and with no leaks. I know it's a different motor, but I went with a Geba with metal impeller for my 996tt motor that is getting rebuilt here soon as I'm just waiting for some parts to show up. The Geba is made in Germany too. I have file photo of a pump with a metal impeller, if you want to see that?
-Jason
A local Porsche "guru" with 40+ years of experience advised me to use the composite impeller (Pierburg or Porsche) as a cast metal impeller will eat into the engine case if a bearing fails. He said there is no way to fix it when that happens.
I've read quite a few threads & articles and it looks like there are pros and cons to both. Ultimately I think it comes down to a Coke vs. Pepsi kind of thing!
I haven't had a water pump failure but I had mine replaced just to be on the safe side. I looked at the old one and if the metal propeller is the same design as the stock Porsche one is then the fins will not just bend, they will rub and grind and cause metal from the case and the pump to be shed.
+996
I'm pretty sure Jake has the same thinking if that's not who you're referencing.
This has been an ongoing debate not isolated to just Porsches. The consensus among the pros is that it's always better to use the composite version for the reason mentioned above.
I think you misunderstood what I was saying.
I would rather go with OE that has the composite impeller and change out the pump every 50-60k miles as a PM rather then have metal impellers and risk damage to the engine case.
Also, even if your composite impeller shreds itself into pieces and goes into the engine, cleaning it out is a lot cheaper then buying or rebuilding an engine.
"even if your composite impeller shreds itself into pieces and goes into the engine, cleaning it out is a lot cheaper then buying or rebuilding an engine."
Not if your engine "milkshakes" or blows up before you figure out that the impeller has "shredded itself into pieces" and clogged up your cooling passages...
Having rebuilt an M96 that had a composite w/p failure, I can assure you the composite fragments also 'polish' the case half housing for the w/p !And the distributed fragments will do much worse damage !
I am guessing that the metal impeller and it's failing bearing(?) would give plenty of warning it was needing repair? The noise should alert an attentive driver? Or does the metal impeller version fail silently ?The coolant loss from the worn bearing should also be obvious and gradual ?
If the failure is sudden, I agree ,they are a bad & worse choice.
Seems maybe the composite is wrong. Maybe PET which is the same plastic as soda bottles are made from would be better, it doesn't chip and it can be in the water forever and not go away. They find them ten years later floating in the ocean, sun and salt water haven't phased them, try to rip a pepsi bottle. A new project for Jake, a better water pump.
If you leave a pepsi bottle in the sun for 6 months over here and then come back and touch it with a finger it will just disintegrate into very small pieces.
This impeller thing can almost be a touchy subject like the oil threads! lol
I have both pumps for whatever direction you decide to choose. My price of $245.00 with free shipping in the US is still good for the OEM Pierburg or the Geba. Here is a pic of the GEBA that is Made in Germany with the metal impeller.
Just curious, when you change the water pump, how much coolant do you lose? I've read that there is about 6 gallons of coolant in the system but how much do you actually lose and need to replenish? 6 gallons... seriously?
Just did the deed last week. 3 1/2 gallons. That was using a lift, so the car remained essentially level. I'd guess if you jacked the car up in the rear only to do it, you'd probably lose less.
