5 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHAdvice/Help - White Smoke - 996 C4S
Leading reported evidence
Check block
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
Leading evidence: 'Check block' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check block' (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 · Original poster
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
There are some finicky parts down there that must be installed correctly to have the AOS operate correctly.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Check block
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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
They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc.
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.
5 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
I installed one on my previous motor last summer, solved the issue straightaway.
Asking for advice and direction. I own a 2002 996 C4S. Around October 2020 I started getting heavy white smoke on cold start-ups (both sides/pipes). I brought it to the shop and had a lot of work done. They machined the head, replaced the IMS, checked for bore scoring (there was none), replaced the piston rings, replaced the gaskets, checked the block, replaced the clutch, replaced the AOS, replaced the spark plugs, etc. Well, I still have smoke but its weird. First, the smoke is very white and doesn't smell. But there is a lot of it, fills a garage. Secondly, it only happens when I drive the car and bring it over 5K RPMs. I never bring it to redline or even close. If I drive the car and never take it above 4K RPM, no smoke and no issues. Only when I start to get on it, the next cold start will be tons of white smoke. I have had the AOS replaced twice since this started again and my shop just doesn't give me an answer to the cause. There are no performance issues, it drives really well in my opinion. Does anyone have any advice? it would be very appreciated.
A couple of thoughts,
The Porsche OEM AOS is very unreliable, the only thing reliable is to properly test with a manometer for proper operation. I have seen brand new ones be faulty right out of the box, and yes sometimes even two in a row.
The other thing is that this a "new engine build" that it's self throws up red flags to me. IF the scavenge pumps are incorrectly orientated it will also cause this. The scavenge pumps are the same bank 1 & 2 BUT they have numbers 1-3 and 4-6 on them and these numbers MUST be on the crankshaft side of the corresponding banks, else they will pump oil INTO the heads instead of OUT of the heads.
Another thing is ring seal, putting new rings on old Locasil cylinders sometimes doesn't work. A "blow-by test" will confirm this. See the thread on "Engine Health - blow-by test"...
I would start by testing AOS with manometer. then verify scavenge pump orientation.. and lastly test blow-by...( most shops don't know how to test engine blow-by....)
I am saying AOS, yet again. I installed one on my previous motor last summer, solved the issue straightaway. There are some finicky parts down there that must be installed correctly to have the AOS operate correctly. Is there oil residue or oil at all inside your intake tubes? Check that first.
White smoke is water vapor, I think. Water is getting into the exhaust system somehow. I would think a cracked head would have white smoke coming from only one side. I doubt both heads are cracked and head gaskets on this car don�t fail, so again, it�s not that for both sides.
I would also check the intake side. Can water be getting into the intake somehow?
This is a source reference. Confirm exact model applicability in the original material.
