11 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH5 year old water pump
Reported or suspected cause
imminent bearing failure allowing the impeller blades
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
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Discussions that report identifying a cause
1
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Reported cause
The issue is imminent bearing failure allowing the impeller blades to rub and break off ending up inside your engine block/heads.
Leading evidence: 'imminent bearing failure allowing the impeller blades' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'imminent bearing failure allowing the impeller blades' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Replace /rebuilding the engine' (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.
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Discussions that report identifying a cause
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Reported cause
And yes, I replaced my water pump and it turned out to be smart because the previous owner had put in the metal impeller!
Replace water pump (and thermostat) proactively at around 120k miles
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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Performed · outcome unconfirmed
For context, my 99 C2 has 148K miles and I replaced the water pump (and thermostat) proactively at around 120K miles.
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
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Performed · outcome unconfirmed
And yes, I replaced my water pump and it turned out to be smart because the previous owner had put in the metal impeller!
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.
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
If the issue is age related and perhaps PH interaction vs heat cycles - then the impeller just sitting in the coolant for 5 years would be the same as it being in use for 5 years.
age related and perhaps ph interaction vs heat cycles
No successful repair reported for this finding.
0
Identified cause
1
Suspected cause
0
Reported fixes
Read evidence and context
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.
Suspected cause
If the issue is age related and perhaps PH interaction vs heat cycles - then the impeller just sitting in the coolant for 5 years would be the same as it being in use for 5 years.
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.
11 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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Generation: 20261027T144324Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
I replaced my water pump in 2018. Car is a 2003. It was replaced with an OEM one as well as thermostat. Car had 45000 miles when replaced. Now has 50000 miles. So water pump has at most 5000 miles.
Would you replace?
To put it in context, my subaru outaback has an original water pump when car was traded in at 200000 miles. My jeep wrangler has an original water pump. 8 years old, 130000 miles.
Look, I don't want to cause any trouble and you have to do whatever makes you sleep at night, but 5K miles on a water pump is nothing. I would plan on replacing at around 70K miles (15K miles from now). Keep an eye on it for any play or seepage from around the shaft, or loss of coolant. For context, my 99 C2 has 148K miles and I replaced the water pump (and thermostat) proactively at around 120K miles. There was slight seepage at the shaft. The OE water pump impeller blades were fine. Like I said, do what you want, it is your car.
I'm not disagreeing. I just hear lots of recommendations around not going more than 5 years on a water pump which perplexes me. As does the years on IMS versus mileage. (I put the solution in so not worried about it).
I get that stuff ages. Only water pumps that I've ever changed was on a couple fox mustangs because they were seeping. All my other very high mileage, fairly old cars, have never had a water pump changed.
It personally wouldn't bother me to continue running the pump and monitoring the shaft play, but not everyone is comfortable with doing that. Mileage is only part of the equation when it comes to replacement intervals. Regardless of your low mileage, the pump shaft bearing has spent 5 years under tension via the belt drive (unless you are relieving the belt tension during long periods of unuse). The issue is imminent bearing failure allowing the impeller blades to rub and break off ending up inside your engine block/heads. Some will say for the cost it's not worth the headache, others are comfortable periodically monitoring the shaft play to decide on when replacement is warranted. As DBJoe996 said, go with whatever helps you sleep better!
My only concern would be the composite impeller. As we know with most Euro cars (positively on BMWs) - the plastics/composites used on the cooling system degrades over time and heat cycles. The question is - is it more over time, or heat cycles or a combination. Or is it due to the coolants PH acting on the plastic/composite parts? If the issue is age related and perhaps PH interaction vs heat cycles - then the impeller just sitting in the coolant for 5 years would be the same as it being in use for 5 years. If that is the case - change it.
If it is heat cycle related that causes the failure of the composite impellers (and other plastics/composites - think end tank couplings, AOS couplings, etc) then the low mileage would indicate few heat cycles - then your water pump would be fine.
I'm not sure the actual cause has actually been identified.
-Tom
Wouldn't it be great if someone would build a water pump for our cars that had an "integrated backing plate" ? Then we could use metal blades without worry of killing the block. But as with many things in the Porsche world, " the juice is not worth the squeeze".......
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The problem with the water pump on this car versus your Subaru, Jeep or other is that the impeller is not made of metal. If the composite made fins break off, which they can and do, they can lodge in the engine and create hot spots where there is no coolant flow which can cripple the engine. There is a metal impeller option but in this car, it risks destroying the block if the main water pump bearing fails. The way to protect your engine is to buy the water pump with the composite impeller and replace it every 5 years.
The only reason I know this is because I have been studying this vehicle for 5 years, two of which were pre-purchase! And yes, I replaced my water pump and it turned out to be smart because the previous owner had put in the metal impeller!
