21 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH2004 996 C4S engine scavenge pump failure
Reported or suspected cause
scavenge pump
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
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Discussions that report identifying 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.
Reported cause
It was the scavenge pump on bank 1 which started deteriorating slowly.
Leading evidence: 'scavenge pump' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'scavenge pump' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Clean offending unit it turns much smoother' (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 contain suggestions
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Suggestion
After dismantling, finding fine particles and cleaning the offending unit it turns much smoother.
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
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Suggestion · Original poster
A rebuild is being recommended between $9,250 to $14,000.
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.
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Suggestion
I reached out to FSI and they recommended a rebuild still.
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
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Suggestion
I theorize this is from a bit of something off the other side's variocam which was running metal to metal, zero guide left.
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.
21 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.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
Exchanged it for a new one and it solved the problem.
Apparently, my scavenge pump failed, causing significant engine damage. A rebuild is being recommended between $9,250 to $14,000. The car has 40k miles. Anyone have this happen and the repair? Any thoughts. advice? Invest in the car? Everything else works great.
Not sure? They found metal filings in the oil and think it is only one shaft that is damaged. However, they need to take the engine apart to determine full extent of the damage.
I have seen several scavenge pumps fail. Everyone I have seen fail was actually "collateral damage" from a failed timing chain roller.
The timing chain lost a piece of one of the rollers and it got sucked up by the scavenge pump. Scavenge pump internal clearance is tight and any piece larger than a pin head will cause damage to it or lock it up.
From there the damage can be minor or catastrophic. Sometimes the pump locks and just breaks the drive snout. Sometimes it beaks the exhaust cam gear. Sometimes it breaks the timing chain and valves start hitting the pistons, so the extent of more collateral damage can vary greatly !!
I have an engine that suffered a SP failure. I took off the heads. Fortunately no valve or piston damage. The damage I did notice was a broken cam gear, timing/cam chains, chain guides, and random metal in the oil pan from the broken SP gear that fits into the cam gear.
I was hoping it is fixable but it really is best to rebuild the engine. I reached out to FSI and they recommended a rebuild still.
How many miles on that engine? Sounds like its fixable to me, but , yea, it's always good advice to do a complete rebuild. You can always pretty much justify a complete rebuild.
BrianF,
I sent you a PM.
2002 3.6 L with 107K miles.
Here are some more details on the failure:
https://rennlist.com/forums/996-foru...e-not-mad.html
If you think you can fix it, PM me. I can send you the pics I have.
Here also some experience with failing scavenge pump at around 115.000 miles.
It was the scavenge pump on bank 1 which started deteriorating slowly.
Symptoms were that over time more and more oil was being spitted out via the AOS vent line. This occurred especially when making right hand turns. The oil would pile up in the head due the lateral g-force and the lack of pumping capacity there would cause too much oil staying in the head and flooding the AOS. The extra pressure in the crankcase was enough to push out enough oil. At the end almost 175ml of oil came out just taking one long 180� right hand turn on a highway ramp at moderate speeds 35-45mph. I had my AOS line rerouted so luckily the oil did not end up in the intake. So It saved me from a catastrophic hydro lock.
No real damage to be visible noted on the scavenger pump itself, some scuffs and light scars on the side surfaces of the gear. Only testing it for pumping capacity would show it had a much lower capacity. Further no collateral damage to be seen on other at first sight. Exchanged it for a new one and it solved the problem.
dont bother with Rebuild unless you plan to go full out like 3.8 or 4.0 with Forged Internals and IMS Solution.
You can get a New Shortblock for Porsche now for 7k and be on your way
Is it me or does it seem like a lot C4S 992 cars are dropping like flies these days?
OP, sorry to hear about the damage. I agree with Zookie. But I wouldn't put another M96 shortblocks. I would pay Flat 6 to reconstruct the engine.
yup i just did mine (18 months in the build) picking it up this weekend
looking at the final bill vs a new shortblock
i would never build it again, id do the short block and call it a day
I agree with others, what ever cost you think it will be double/triple it...Tools alone are going to set you back just to get started.
Again, sorry you have to deal with it like this...
I would vote for a short block myself. Send the heads out for a valve job if it has 100K miles or more. While it is out, order the short block.
Once everything is in, it is a 40 hours assembly job from there.
18 months and 3 times the cost? No thanks.
Sorry to ressurect this oldy, but I was researching the cause of this and came across this great information. I imagine it's one of the most common issues we're facing these days and thought yall might like to see "minor". Based on Porschetech3's experiences I think I dodged a MAJOR bullet here! I theorize this is from a bit of something off the other side's variocam which was running metal to metal, zero guide left. Both pumps turn somewhat stiff. After dismantling, finding fine particles and cleaning the offending unit it turns much smoother. I'm in the engine of this '99 Boxter 2.5l because of previous owner's dealership assessment of variocam guide failure on bank 2 and p0304, 05, 06 codes, just happened across this while reassembling bank 1. I was able to find a used sprocket for $28 bucks!
