Petza914

There is scoring in those photos - the multiple vertical lines together in some of the photos are the scoring, and the silver color on the top of the piston crown in some of the others is vaporized and deposited aluminum. I would guess that a UOA report will show some higher than normal Aluminum, maybe in the 12-14 ppm range.

I would suggest going to an oil with higher hot film strength like a 5w50 - I think LiquiMoly offers one and my personal choice would be Driven FR50 to prolong the life of the motor. If the car is still at the Indy, have them hook up a manometer and see what the crankcase vacuum number looks like - my guess is it will be a little lower than it should be as some combustion pressure makes in past the rings via the scoring lines, so maybe a 4 number when you want it closer to 5 or 6.

groovzilla

Petza previous owner of my car used LiquiMoly and I continued.
The scoring on the OP's cylinder walls looks very minor. Normal for 120K miles compared to other scoring photos I have seen.
My indy was amazed to see my cylinder walls without any rub marks but I think that is not normal.
Your take?

onnastick

Thanks very much. Today I did send the used oil over for a Blackstone analysis - will update this thread once I get the report.
Based on some other reading across this forum, I had the indy put in Driven DT40 - which is what I was planning to start using. That was before I had received any photos or any forum feedback. I already received the vehicle back. If you think FR50 would be superior for this engine I can transition to that at next OCI. No clue what the PO used. If you think it's warranted, I can also ask them to check the pressure next time I take it in, to see if the numbers bear out your suspicion.

In terms of an overall "what do I do here" I am thinking at this point there's no reason (yet) to believe this is all recent and advancing quickly and I need to take immediate and radical action. Rather, get another scope, more UOA, and take other measurements at future service intervals and compare the results to look for changes. And to hope that if it appears to be getting worse that it will be a very slow process. Let me know if you disagree.

Petza914

If the car runs fine, drive it. I would move from the DT40 to the FR50 at your next oil change though - no need to do it before as I run DT40 in my wife's 997 with 110k miles and in my Twin Turbo Cayenne with 650HP. DT40 is great and what I'd recommend you use if I didn't see the light scoring marks, but with them, think you'll prolong the life of this motor with the switch to FR50. If you have an Indy do your oil changes, by all means have them hook up the manometer and have them take readings at idle and 3,000 RPM to see what the crankcase vacuum/pressure numbers look like. Pulling mean fuel trim #s for bank 1 and bank 2 may also tell you something, especially if they show numbers below 1.0000 which is what the DME tries to achieve. If they drop below 1.00000 to like a 0.98xxxx it means the DME is sensing a rich condition and pulling fuel, leaning out the mixture. If you have some scoring this is the direction the fuel trims will move.

Don't panic as you'd know if you had a scoring problem that was bad enough to warrant a rebuild or not - at some point you may get there but if tracking cylinder misfires in live values and you're not seeing any, that means your compression is still good enough to not be causing misfires. No one can tell you how long the engine may go like this - scoring never gets better, only worse, but how long until oil consumption is high and misfires from lower compression begin is hard to guess.

Installing the LN Engineering low temp thermostat will also help as it allows the engine to warm up more gradually so the block and the pistons expand at a more similar rate instead of the pistons growing faster.

Ericson38

What I noticed from your images is that they took pictures of all cylinders, but did not rotate the engine through, so that all the pictures would have pistons at bottom dead center, so that a big part of cylinder surfaces could be viewed. That's most likely why they only charged what they did. Wherever the engine was at rotation wise at the time dictated the pictures you got.

You mentioned that they did not # the pictures, so you know which image was related to which bore. These engines are more problematic on the right side cylinders.

linderpat

I think we should be more precise about this. There would be no impact or increased risk of a 997 from a very cold environment that is stored during the cold season and not driven. Most enthusiasts in these climates put away their cars when it starts to get cold, and don't bring them out again until the warmth of spring. I think the more important metric is whether it is regularly driven in the cold, and if so, what precautions were/are taken.

Petza914

Yea, if it sits in a garage when it's cold, that doesn't matter. I can look under a 997 for 15 seconds and know if the car was ever used in the winter driving months - white corrosion on the aluminum engine parts, air injection pump cover rusted, all the steel fasteners with rust on the heads.

If you pull a Carfax on a car you're considering, look for service entries from November to February in cold climates as that will be an indicator that the car wasn't stored for winter.

groovzilla

More precise?? I think my observations are very precise.
With these cars reaching 15- 17 years old, there is no way to know for sure whether a car has been stored all winter or started/driven occasionally especially with multiple owners over these15- 17 years. Just isn't possible to know for sure.
Besides many sellers like to Bullsh:t and not forthright. Clueless.
This is why a Bore Scope Inspection is your friend especially on cold weather cars.

However maybe there are ORIGINAL owners selling who have years of winter storage videotape to prove car hasn't been started. A longshot but maybe a chance

And Petza, as far as oxidation it can be the opposite.----> Any car spending long periods of time in Florida on coast will almost for sure see oxidation on engine case and other components/brakes/etc.
So oxidation isn't necessarily a telltale sign of living in cold weather

Heres's a case in point---> Florida car oxidation and what I'm referring to:

bgoetz

As Petza mentioned there is definitely scoring in those pics, the one is noticeably worse than the others, but since it is from the top it is hard to say just how bad it really is. I would follow his advice and just monitor for noises and oil consumption and start thinking about what you might want to do should you start to have noticeable issues (rebuild or part ways with the car).

If you take precautions you should have a lot more time to enjoy the car, which is good because even if you wanted to do something now, I don’t think you could have anything done for a couple of years. The worthwhile builders who have parts are backed up for years and the rest can’t get parts for years due to supply issues.

Ericson38

The pictures from the OP's inspection don't cover all the surfaces one would be examining for scoring, since the engine was not rotated between shots. See this to get an understanding on why some pictures are only of piston tops-

groovzilla

The slight scoring in those photos seems normal for a 120K mile engine.
Ring rubs look light and I don;t see any "hot" spots or cracks but maybe I'm missing something? What are cylinder walls expected to look like at 120K miles. They won't be perfect

When I had my BS Inspection in November on my 106K mile C4, my 50 year Porsche Indy remarked he hadn't seen cylinder walls so clean before and was very surprised.
So I assume some light scoring is normal at 120K miles.
Anyone care to elaborate?

bgoetz

I think all anyone can say from the pics is there is scoring period. How bad, is just a guess because the pics are from the top, but to me the one pic does have noticeable scoring. As for if all 120k mile engines look the same? Who knows, the sample set is super limited. For a point of reference that is about how mine looked and I got a knock, so it is heading to FSI. I can report more on just how bad mine was once they have it apart.

Cracks like you observed are not really related to scoring.

onnastick

I'd like to have better photos, but I have neither the tools nor knowledge to do it myself. How hard is it to do, for someone who hasn't ever really "turned a wrench" as you say?
I kind of feel bad having to try and explain to the indy what I need from the photos. What you are saying makes sense to me - better perspective to see more area, rotate the engine between shots so we can actually see the walls (not all pistons will be out of the way without moving), number the cylinders so we can see which ones are in which shape). I understand after your explanations here. But, I don't understand why this wasn't obvious to them already. I'm afraid if I bring it back again next time I'll get similarly incomplete photo documentation of the cylinder state. Without which it will be hard to figure out where I stand and whether the condition is worsening slowly or quickly.

Petza914

Here's the question ... what are you going to do once you have the better photos? Are you going to just drive the car like you don't know about the photos, are you going to put your name in the queue at Flat 6 for their next build slot and hope the car makes it to that spot 18-20 months away, sell it (hope not this one), etc?

onnastick

Good question. Sorry if this answer is too long. The short version is I don't know. I know that when I purchased the vehicle a few months ago as my first Porsche, it was not my intent or belief that I'd have to spend almost that much money over again to put in a new (albeit amazing) engine. I was hoping I could daily drive it for perhaps up to a few years, spend appropriately to keep it in good operating condition, and enjoy it along the way. And sell it at the end, still in good operating condition. So to answer your question, I hope the engine's condition is not going to degrade quickly, but instead quite slowly. So that I can enjoy it, as can its next owner and so on. And photos would hopefully help me understand if this is possible, i.e. if I can see anything changing.

Full disclaimer: aside from this being my first Porsche, I've also never owned a car this age. I've had a habit of mostly buying new cars. I am not suggesting that is the smart choice, it's just what I have done. So the whole concept of starting down a road towards needing an engine rebuild (just a question of when) is completely unknown to me and quite scary. I've never owned a vehicle that had that kind of expensive work done to it.