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THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH996 Water Pump from Bosch
Leading reported evidence
Fill cooling system
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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Discussions that contain suggestions
1
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Suggestion
Remember, its a bearing failure that makes the plastic impellers break off and fill the cooling system.
Leading evidence: 'Fill cooling system' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Fill cooling system' (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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Suggestion
Do you know if they recommend metal impellers for the 996?
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Suggestion
If I recall correctly, water pumps should be replaced based on mileage and time in service (4 years?) so if I'm going to replace it periodically why wouldn't I use the factory spec item?
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Suggestion
If I recall correctly, water pumps should be replaced based on mileage and time in service (4 years?) so if I'm going to replace it periodically why wouldn't I use the factory spec item?
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Suggestion
When our tandem bearing pump was available no one would spend the money for it, so they were all used on our engines only.
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Suggestion
If I recall correctly, water pumps should be replaced based on mileage and time in service (4 years?) so if I'm going to replace it periodically why wouldn't I use the factory spec item?
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
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Suggestion
If I recall correctly, water pumps should be replaced based on mileage and time in service (4 years?) so if I'm going to replace it periodically why wouldn't I use the factory spec item?
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Suggestion
owning alot of german cars, they all use plastic and they all need to be replaced around 40k....for me....i think its a parts game more than a true technical need...but again...thats me being cynical to the german plastic style.
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21 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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Generation: 20261026T103553Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
FWIW, one of our local indy shops -- well-respected and very experienced -- prefers to install pumps with metal impellers. This blog post lays out their rationale:
http://www.bavarianrocketscience.com...ng-water-pumps
Definitely another point of view ... I was in the "plastic impeller" camp, but now I'm not so sure.
The short answer is because experts like Jake Raby tell us not to.
When your pump fails, and they all do at some point, you don't want metal on metal shearing your case.
It is certainly a point of view. Do you know if they recommend metal impellers for the 996? The blog post does say "some designs require plastic, as metal could do damage as well. In some engines the water pump is located very close to the engine block and if a metal impeller was to fail and score the block from rubbing against it, major damage can occur." It seems that they're saying that (1) replace your pump every 30-50k miles, (2) you can hear metal impeller pumps going bad, (3) get your car regularly maintained.
I'm not sure that I buy it though. If I recall correctly, water pumps should be replaced based on mileage and time in service (4 years?) so if I'm going to replace it periodically why wouldn't I use the factory spec item? Also I'm not sure what to listen for to know if the metal impeller pump is going bad and how long I have before it starts engine gouging.
About the same chances as having a bearing failure and the cooling system being filled with chunks of metal as the metal impeller becomes a "milling machine".
Remember, its a bearing failure that makes the plastic impellers break off and fill the cooling system. Until someone steps up and makes a tandem bearing pump (like we already designed) the units simply won't be robust enough, no matter what. The metal impeller is also heavier and that increases load on the bearing.
When our tandem bearing pump was available no one would spend the money for it, so they were all used on our engines only.
Actually, yes, they do recommend metal impellers for the 996 ... I had occasion to ask the post's author about this. His viewpoint definitely took me by surprise. In your last sentence you've stated the two issues that had put me in the plastic impeller camp in the first place.
Interesting, my assumption was a metal impeller rarely if ever sheers out and fails like that....i mean i have never heard of it but its not to say it can't happen...
but if it can and has happened with some regularity...then yes plastic is understandable.
owning alot of german cars, they all use plastic and they all need to be replaced around 40k....for me....i think its a parts game more than a true technical need...but again...thats me being cynical to the german plastic style.
My order of the Bosch 97261 / F00E300735 New Water Pump was cancelled by Amazon. No reason given as to why.
There is a Gates pump available for $85 now. Funny thing, in the 924/944 forum they like the OEM Porsche water pumps because they have metal impellers and talk about the cheap composite imitations.
I am pretty sure they never actually had it available - I checked it a few days ago and it showed that the part was unavailable and I haven't had much luck finding a Bosch pump elsewhere either. Bummer, had me all excited
