16 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH3.0SC Engine Rebuild
Leading reported evidence
Replace before
Performed · outcome unconfirmed
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 performed work without a confirmed outcome
1
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Performed · outcome unconfirmed · Original poster
The pistons and cylinders had obviously been replaced before..
Leading evidence: 'Replace before' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check sprocket/chain alignment' (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
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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'm certain that the cylinders and pistons have been replaced not that many kms ago, but several years at least as it was before the current owner possessed it.
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
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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
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Suggestion · Original poster
Didn't take pics of timing or checking valve clearances, but it's been done and I am within 0.01mm variance from left to right.
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.
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'm certain that the cylinders and pistons have been replaced not that many kms ago, but several years at least as it was before the current owner possessed it.
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.
16 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Porsche Forum Australia: 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: 20261026T183130Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Let's see if photos are working for me...
OK, so photos now seem to be working..
This is a 3.0SC motor that has travelled enough kms to go to the moon (and start its return journey). Owner reported at least one broken stud and lots of oil leaks. There was no history of a prior rebuild so I went exploring.
Look at all that crud.. surprisingly not as bad as I would have thought for over 400,000kms??
Blocked oil cooler..... "normal"....
Air injection tubes still attached but blocked off... what's my screwdriver pointing to???
yep, chain box stud working its way loose.. never seen that before?
That's a lot of oil running down the side of the case
rocker shaft leaks
pinched oil cooler o-ring...
Valve stem seal halfway up the valve stem!
bits of old chain rail found throughout timing gear
rod bearings
removing original head studs
After a LOT of cleaning we have
Still, several more hours are required to get to...
Now time to start assembly...
Crankshaft measured well with spec.
The pistons and cylinders had obviously been replaced before.. some of the cross hatching was still evident in the cylinders and there was no obvious wear at the tops of the cylinders from the rings as you normally feel with high mileage motors. All piston skirts still had their machining marks and were not polished smooth.
I'm a bit of a stickler for measurements... bolted all rods together with bearings... all clearances except one were good... Pulled the bearings out of the suss rod.. measured the rod... it was sized perfectly.. suspected the bearings... turned out one of them differed in thickness across the face of the bearing, by 0.12mm !! Yep, that's a lot... into the bin and got a new set.
cc'ing heads.
If you've ever worked out the actual compression ratio for stock pistons from Porsche, 9.8:1 pistons do not measure anywhere near 9.8 in reality!
Getting the case ready for assembly.
click your fingers and hey presto!
Starting to look like a flat six motor now...
Checking sprocket/chain alignment... left side was bang on perfect.
Right side was within spec but not exciting enough to take a photo!
Somewhere in the middle of those two options!
Bruce, I didn't drive it much before tear down.. just enough to get a feel for the gearbox and warm the oil to drain it all.. it didn't appear to blow much smoke but did have a leaky sounding exhaust.. possibly from the broken headstud. I didn't lean on it much on the drive, so cannot comment on if it was down on power much.
I'm certain that the cylinders and pistons have been replaced not that many kms ago, but several years at least as it was before the current owner possessed it.
I'm looking forward to getting it running again.
Getting ready to set the camshaft timing
Didn't take pics of timing or checking valve clearances, but it's been done and I am within 0.01mm variance from left to right. I think that will do.
