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I have to say we are really fortunate that the experts are willing to spend time on these boards to help us get to the bottom of these things.
So here's some photos to compare of a scored piston with a spray-on/printed coatings vs. a scored 9A1 piston. This photo is from a scored Cayman with printed coated. You can see the clearly defined coating edges, the relatively smooth coating surface in the undamaged areas, and evident flaking of coating in damaged areas. This shows the characteristic M96/97 scoring in the center of thrust face and is typical of virtually all scored M96/97's that I've seen.
Here's another photo of a printed coating Baz previously posted over on Jake's bore scoring duo post. This is ferroprint that started to flake but hadn't yet scored. The same characteristics of the printed coating are seen here (smooth surface, defined edges, flaking).
Now here's a photo of Bronz's scored 997.2 9A1 piston that Charles had posted a while back (thanks for documenting this Charles!). Right off the bat it's obviously different as the scoring is on the edges of the skirt, and both sides of the piston, rather that the thrust face center. This is the "seizing" phenomena Baz has documented.
But notice that what remains of the coating looks completely different from the previous photo. Note that in the unscored center you can clearly see the horizontal ridges of the piston surface that are mostly hidden by the smoothish surface of a printed coating in the previous photos. There is no obvious printed coating apparent at all despite the fact it's completely unscored in this area. There is also no obvious flaking of smooth printed coated surface anywhere on the piston. I'm not an expert on this but it looks electroplated to me as the a plated coating is thinner and conforms more closely to the piston surface than a printed coating would. The only other conclusion could be that all traces of a printed coating were worn off but that doesn't seem credible.
Anyways, I'm throwing this out there so the smart folks who are trying to better understand this have something to consider. Based on the very limited evidence available there do seem to be clues that the 9A1 engine doesn't use the same piston coating as the M96/97.
Thanks again to Charles for posting great information on the 9A1 failure over in the thread on Bronz's engine.
LOL another 6 page bore scoring bonanza (and will prob end up at 20 pages but nah we dont need a sticky to keep them all in 1 place; people love talking about this ****)
Same old desperate hopefulness, dejected resignation, fanboys and truth slayers as always
What made us look deeper into mine was the low manometer reading and then silver coloration on the tops of the bank 2 piston crowns. We believe this is tiny bits of aluminum that are melted and burned onto the top of the piston crown. Someone said why go looking for this if there's nothing you can do about it. The reason is that there is some preventative stuff you can do about it to prolong the interval from when it's discovered before it has to be rebuilt. Since I can't afford to do the rebuild the car deserves, I'm planning to drive it this way for a while with these changes.
Because I live where it's fairly warm, I'm changing from Driven 5W/40 DT40 to Driven 5W/50 FR50. This will provide additional film strength from the oil to minimize further wear from occurring in the bores.
The tops of my pistons and my spark plug electrodes look burned from being too hot so I've gone to a colder spark plug to try and lower the temperature in the combustion chamber. Some of this heat may be a result from the forced induction with the supercharger, but in either case cooler will be better as long as it doesn't result in misfires which will be easily detected by the DME
Reducing my oil change interval from 4,000 miles to 3,000 so there is more Zinc & Phosphorous remaining in the oil at the change interval. This is the anti-wear additive package that was the first clue from my UOA that something wasn't right as those two components were lower than they should have been in the last UOA for the DT40 oil being used and the mileage on it.
These black spots on the rear bumper was the cause for the start of the investigation - this is evidence of the car being over rich (likely caused by the vacuum leak located behind the alternator)
Tops of the piston crows - should be black, not silver
Close up view of another one - we think the yellow flecks might be Stabil 360 fuel stabilizer that I run
Spark plug that's too hot
No glimmer in the oil - the things that look like something are bubbles
Nothing in the pickup
Super clean engine internals
Nothing in the pan either above or below the windage tray
I agree with you, I didn't mention anything that contradicts that. Probably my next vehicle will also be 997.2 (if I don't find 993
Regarding the 993 purchase---->Make sure the Air Passages in the heads are not clogged with carbon and are clear/clean - or make sure engine has had top end rebuild
What made us look deeper into mine was the low manometer reading and then silver coloration on the tops of the bank 2 piston crowns. We believe this is tiny bits of aluminum that are melted and burned onto the top of the piston crown. Someone said why go looking for this if there's nothing you can do about it. The reason is that there is some preventative stuff you can do about it to prolong the interval from when it's discovered before it has to be rebuilt. Since I can't afford to do the rebuild the car deserves, I'm planning to drive it this way for a while with these changes.
Because I live where it's fairly warm, I'm changing from Driven 5W/40 DT40 to Driven 5W/50 FR50. This will provide additional film strength from the oil to minimize further wear from occurring in the bores.
The tops of my pistons and my spark plug electrodes look burned from being too hot so I've gone to a colder spark plug to try and lower the temperature in the combustion chamber. Some of this heat may be a result from the forced induction with the supercharger, but in either case cooler will be better as long as it doesn't result in misfires which will be easily detected by the DME
Reducing my oil change interval from 4,000 miles to 3,000 so there is more Zinc & Phosphorous remaining in the oil at the change interval. This is the anti-wear additive package that was the first clue from my UOA that something wasn't right as those two components were lower than they should have been in the last UOA for the DT40 oil being used and the mileage on it.
These black spots on the rear bumper was the cause for the start of the investigation - this is evidence of the car being over rich (likely caused by the vacuum leak located behind the alternator)
Tops of the piston crows - should be black, not silver
Close up view of another one - we think the yellow flecks might be Stabil 360 fuel stabilizer that I run
Spark plug that's too hot
No glimmer in the oil - the things that look like something are bubbles
Nothing in the pickup
Super clean engine internals
Nothing in the pan either above or below the windage tray
The light scoring in #6
Same #6 with slightly different lighting
Yeah, the oil spray on the bumper would have freaked me out too. Hope you can find the vacuum leak easily that may be causing the fuel richness. Although even with rich fuel, how is that much oil being introduced into the system to cause the black oil spray on the bumper? hmmmm... It's like something I would expect to see coming out of a 2-stroke engine with oil mixed in the fuel... strange. I gotta say, based on the many scoring pics we have seen over the years, this looks very minor and caught very early. Your oil and oil pan looks super clean. Not sure if you caught my question earlier in thread, but what does your latest oil analysis say? Are you seeing increased metals / silicon in the analysis?? I would think you would have seen some sort of tell tale signs...
Petza, sorry man. That sucks, but is does not look bad. Don’t you think a lot of what you are seeing on plug and piston could be from forced induction and needing a tune. I have seen this in some of my cars in the past for a variety of reasons.
Petza - Thanks for posting these and agree with the others that it looks like you found it early. Please keep us posted on how the mitigation measures work out.
Just to note that the OP who started this thread four days ago (and has only two posts) has not returned. There has been no VIN posted, no follow up information, no info on who performed the PPI, and nothing about the qualifications of the technician. In other words, nothing that actually advances the conversation. Pretty typical.
For all the talk of this being a "great community" there are many people who seem to be little more than trolls. When I first started posting here I naively thought most of the commenters love these cars and actually wanted to share information and learn things from each other. That's the reason I put together my PDK sticky as I spent a lot of time researching it, it is fact-based, and thought others would find it helpful. The Bruce's buyers guide is another example and a fantastic resource he put together for free. Petza's comments are always informative and fact-based. So those people are here no doubt, but it's certainly not all the commenters. There's one guy five posts up the page who's bio says he's been here over ten years but only seems to show up to insult people (anonymously of course). There's all sorts of uniformed opinions that are never prefaced as such but stated as fact (such as continually conflating 997.1 and 997.2 bore scoring despite the fact they are nothing alike). Not surprising as it's the internet after all where everyone gets to pretend they are an expert, but God help the newbee who's actually trying to make informed decisions regarding their $50k car.
Sorry for the rant but for those new to the 911 looking for honest information please do your research rather than taking what you read as fact. There's great information here but there's also a huge amount of nonsense being regurgitated.
petza thanks for the post - does your car have LTT or 3rd rad installed?
Originally Posted by Petza914
What made us look deeper into mine was the low manometer reading and then silver coloration on the tops of the bank 2 piston crowns. We believe this is tiny bits of aluminum that are melted and burned onto the top of the piston crown. Someone said why go looking for this if there's nothing you can do about it. The reason is that there is some preventative stuff you can do about it to prolong the interval from when it's discovered before it has to be rebuilt. Since I can't afford to do the rebuild the car deserves, I'm planning to drive it this way for a while with these changes.
Because I live where it's fairly warm, I'm changing from Driven 5W/40 DT40 to Driven 5W/50 FR50. This will provide additional film strength from the oil to minimize further wear from occurring in the bores.
The tops of my pistons and my spark plug electrodes look burned from being too hot so I've gone to a colder spark plug to try and lower the temperature in the combustion chamber. Some of this heat may be a result from the forced induction with the supercharger, but in either case cooler will be better as long as it doesn't result in misfires which will be easily detected by the DME
Reducing my oil change interval from 4,000 miles to 3,000 so there is more Zinc & Phosphorous remaining in the oil at the change interval. This is the anti-wear additive package that was the first clue from my UOA that something wasn't right as those two components were lower than they should have been in the last UOA for the DT40 oil being used and the mileage on it.
These black spots on the rear bumper was the cause for the start of the investigation - this is evidence of the car being over rich (likely caused by the vacuum leak located behind the alternator)
Tops of the piston crows - should be black, not silver
Close up view of another one - we think the yellow flecks might be Stabil 360 fuel stabilizer that I run
Spark plug that's too hot
No glimmer in the oil - the things that look like something are bubbles
Nothing in the pickup
Super clean engine internals
Nothing in the pan either above or below the windage tray
This would not concern me in the least at this point. I do like the approach of taking some proactive measures, but man this thing could possibly go another 70k miles before it needs anything done to it!
Petza - Thanks for posting these and agree with the others that it looks like you found it early. Please keep us posted on how the mitigation measures work out.
Just to note that the OP who started this thread four days ago (and has only two posts) has not returned. There has been no VIN posted, no follow up information, no info on who performed the PPI, and nothing about the qualifications of the technician. In other words, nothing that actually advances the conversation. Pretty typical.
For all the talk of this being a "great community" there are many people who seem to be little more than trolls. When I first started posting here I naively thought most of the commenters love these cars and actually wanted to share information and learn things from each other. That's the reason I put together my PDK sticky as I spent a lot of time researching it, it is fact-based, and thought others would find it helpful. The Bruce's buyers guide is another example and a fantastic resource he put together for free. Petza's comments are always informative and fact-based. So those people are here no doubt, but it's certainly not all the commenters. There's one guy five posts up the page who's bio says he's been here over ten years but only seems to show up to insult people (anonymously of course). There's all sorts of uniformed opinions that are never prefaced as such but stated as fact (such as continually conflating 997.1 and 997.2 bore scoring despite the fact they are nothing alike). Not surprising as it's the internet after all where everyone gets to pretend they are an expert, but God help the newbee who's actually trying to make informed decisions regarding their $50k car.
Sorry for the rant but for those new to the 911 looking for honest information please do your research rather than taking what you read as fact. There's great information here but there's also a huge amount of nonsense being regurgitated.
So PP997 and others who are scorning me for my bore scary post, I AM the PO. I am not a troll nor a first time poster and thanks for making feel like an unwelcome "outsider." To clarify I have been a forum member since 2011, a long time PCA member and Porsche owner & over for over 30 yrs., track junkie one one of the first certified IMF track instructors in north america. If it wasn't for my Porsche love affair I would be mortgage free at this later stage in life. I'm accused of fear mongering and posting then ghosting. For the record, did post up images the porsche dealer tech sent me of the snap-on (not cheap $30 amazon scope criticized by another member) scope shots. Please accept my apologies for those who misinterpreted my original post. Like many of us I've been reading about the issue on gen1's and related questions about it's reality in the gen 2's so thought since I found one in the gen 2 I'd let the forum know. Never anticipated such a vile reaction. I'm only catching up with all the chatter here on the weekend and don't live my life on the forum because I own my own business and jammed for down time through the week, Another member accuses me of throwing around all the right terms but basically don't know what I'm talking about. I do know a little after 30 years of air cooled, water cooled, front engine and rear engine. After replacing 2 air oil separators in my 996C4S and still smoking on hot re-start at the track which I could never replicate on the street no matter how hard I tried I decided to sell it. Tired of all the black flags coming out of the same corner and smoking like a 007 car. See short video the porsche tech sent me of the ppi cold startup. He said it was acceptable. Inconclusive to me. Why? It's winter here, is that smoke or exhaust hitting the cold morning air. It's only about 18 sec, but given the aos replacement history 12k mi earlier I authorized the dealer to look inside totally expecting a no fault found condition. My point in the posting is that even though there are no obvious "lifter" like noises and cold startup smoke is deemed "acceptable", do your due diligence. At a recent track event last fall, one of my driving students picked up the "lifter" noise along with some first time smoke fog on re-start after a 30 min cool down, apparently his second and at the time claimed final porsche disappointment. But just like the rest of us, I'll he'll probably show up in a caymen gt4 next season and back in the love affair. So quit the scorning guys. Lets all be adults. And for those critical - judgemental types, I'm ready for your wave of whatever on the smoking video. Oh, by the way, the reason I didn't post the vin across the internet is that I know the selling dealer, a local high end, high integrity porsche performance shop who has worked on my earlier p cars and I know what it's store for this particular unit. It's all good.
Petza - Thanks for posting these and agree with the others that it looks like you found it early. Please keep us posted on how the mitigation measures work out.
Just to note that the OP who started this thread four days ago (and has only two posts) has not returned. There has been no VIN posted, no follow up information, no info on who performed the PPI, and nothing about the qualifications of the technician. In other words, nothing that actually advances the conversation. Pretty typical.
For all the talk of this being a "great community" there are many people who seem to be little more than trolls. When I first started posting here I naively thought most of the commenters love these cars and actually wanted to share information and learn things from each other. That's the reason I put together my PDK sticky as I spent a lot of time researching it, it is fact-based, and thought others would find it helpful. The Bruce's buyers guide is another example and a fantastic resource he put together for free. Petza's comments are always informative and fact-based. So those people are here no doubt, but it's certainly not all the commenters. There's one guy five posts up the page who's bio says he's been here over ten years but only seems to show up to insult people (anonymously of course). There's all sorts of uniformed opinions that are never prefaced as such but stated as fact (such as continually conflating 997.1 and 997.2 bore scoring despite the fact they are nothing alike). Not surprising as it's the internet after all where everyone gets to pretend they are an expert, but God help the newbee who's actually trying to make informed decisions regarding their $50k car.
Sorry for the rant but for those new to the 911 looking for honest information please do your research rather than taking what you read as fact. There's great information here but there's also a huge amount of nonsense being regurgitated.
Great rant, in fact you have effectively posted the same thing i have been saying all along ie much of the "facts" are pulled from someones *** so do your own research (here and elsewhere) and make your own assessment
Since you cant quite bring yourself to actually name names then i will assume you are referencing me. I insulted no one and in fact i do believe you insulted me once again (anonymously of course). And BTW everyone is anonymous here or didnt you notice that. Lots of people know my real name and if you want it, I'm happy to provide.
THERE IS NO NEW INFO HERE. I suggested a sticky to address this issue in one place ie not have another bore scoring discussion that adds no value by an OP who has never come back. But yet people persist
And you havent even done your homework once again. I have made many contributions to technical questions where i can over the years (but you havent really bothered to check of course)
You seem to fashion yourself as a serious man. Great, congrats. I come here for technical info (which is fantastic) but its also a place to have some fun and not take ourselves so seriously talking about cars, life etc. (like qikqbn or Groovezilla etc, where we can disagree on stuff but still have some fun).
Try it some time. And I know you consider emojis the sign of an immature man but what the hell here goes
petza thanks for the post - does your car have LTT or 3rd rad installed?
Yes, it has both. The 3rd radiator was installed as part of the supercharger kit at 7,000 miles. The LTT was added when I did a water pump at 40k miles, which was 20k miles ago. The car has always been properly warned up below 3,000 miles, spends virtually no time idling, and is so fast, rarely sees RPMs above 5,000.
Ill post the UOA in the next couple days. It did not show anything alarming at all. All wear metals were single digits and TBN was still above the TAN so the oil had not become acidic. It was Jake that picked up on the fact that the Zinc and Phosphorous were low for DT40 and said we need to find out why.
Petza914 - Sorry to hear the updated info on your engine. I've always appreciated your help regarding 997 related questions and think you are great asset to this Forum.
Since I have absolutely no mechanical skills, I have a very simple solution to resolve your latest engine issue.
Next time your wife takes a vacation, strip your engines goodies/wheels/suspension/wing/bumpers/etc and swap/transfer to your wife's car.
De-wrap hers and wrap yours in pink and your done
Petza914 - Sorry to hear the updated info on your engine. I've always appreciated your help regarding 997 related questions and think you are great asset to this Forum.
Since I have absolutely no mechanical skills, I have a very simple solution to resolve your latest engine issue.
Next time your wife takes a vacation, strip your engines goodies/wheels/suspension/wing/bumpers/etc and swap/transfer to your wife's car.
De-wrap hers and wrap yours in pink and your done
Thanks. Good thought, but I'm not willing to give up the extra 125 HP or the suspension setup. Hoping it runs like this for a while. From the way it drives, you'd never know.
02-07-2020, 03:54 PM
(that was for u speedy)
It's like something I would expect to see coming out of a 2-stroke engine with oil mixed in the fuel... strange. I gotta say, based on the many scoring pics we have seen over the years, this looks very minor and caught very early. Your oil and oil pan looks super clean. Not sure if you caught my question earlier in thread, but what does your latest oil analysis say? Are you seeing increased metals / silicon in the analysis?? I would think you would have seen some sort of tell tale signs...
but what the hell here goes 