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Wow, thanks for sharing. Those pics to my untrained eye look like very light scuff marks to me which maybe explains why your oil consumption is not high at all really (1 qt per 4K miles), as the manual quotes even 1qt per 384 miles is within acceptable limits. If I were you, I’d not even get on a list as I think your engine (barring any piston slap or sudden high oil usage) could go on for a way long time without issue. All engines wear from day 1. As for parts becoming more scarce, how do owners of old *** 911s from the 60s or 70s get their engines rebuilt when needed? There’s gotta be a way to still get engine parts for the 997 10, 20 yrs down the road still, and maybe there will be even more options made available for the consumer. I even read in a FB group I follow today that Hartech was going to start sending their cylinders to select shops in North America so that they could use their parts to do rebuilds. If I ever need to do a rebuild, I think there will be more choices out there and that’s a good thing.
Originally Posted by 8KaboveMSL
OP, I also discovered my car had bore scoring in Dec of last year. It had 48k miles on it at the time, showed no consistent noticeable symptoms and was consuming about 1/4 qt of oil every 1k miles. The oil consumption was within "spec" and I didn't have any audible signs (piston slap). I asked my indy to do a bore scope from the top (in addition to a few other things) as I was getting ready to go on a cross country drive from CO to DC. Well, I discovered bore scoring (pics attached for reference below).
I am going to try to answer your question honestly, with the caveat that there is a lot we collectively do not know about bore scoring and how it plays out in the M96/97 engines. I think you have input from folks that have not had to deal w/ bore scoring yet above and all of those are valid responses. I am not writing to rebut any of that. Reasonable people will disagree on this topic because precisely because there is so much we don't know. In the end it becomes a very personal decision as to how to deal w/ either the prospect or evidence of bore scoring. I'll discuss what I did once I figured out I had bore scoring and also give you my perspective on what things I weighed. I do take the BS issue seriously and hopefully that doesn't put me in the hysterical camp.
Here is what I did. . .
Prior to discovering my cylinder bores were scored:
Used DT 40 Oil
OCI - 5k miles or 6 most, whichever comes first
UOA at every oil change
Installed LNE magnetic drain plug
Installed LNE Low Temp Thermostat (LTT)
Installed LNE Spin on filter adapter and used their recommend filters
Kept revs under 3k RPM until Oil temp was close to 200 F
What I have done since discovering the issue:
Reduced oil change interval to ~ 2.5k miles
Started using Liqui Moly 2040(1 liter)/2041(5 liter) Synthoil Premium SAE 5W-40 Motor Oil which apparently has a superior detergent package to improve removal of any metal debris
All of these steps seem reasonable and are not by any way prohibitively expensive, so it all seemed fairly rational to me.
It's pretty clear that once the scoring process starts in the bores, it can't be reversed. The best one can hope for is to slow it down. If you drive the car, it's going to progress. The big question that none of us really know the answer to is: how long can one drive an m96/m97 engine w/ scored cylinders before the condition leads to a serious failure or a more expensive rebuild?
There are a few of us that are at that point in the process and we are trying to determine exactly that. Should we go for a rebuild now? Should we wait? Again the right depends on each one's circumstances. Do I daily my car or only drive it 2k mi/yr? Would I like to get more power/performance out of my engine? There are many other factors to consider, we are not all in the same situation. For me when I looked at the pros and cons this is what I saw:
Pros of doing a rebuild now:
Ensure no unnecessary damage is done to the engine
Parts for a rebuild while becoming more difficult to obtain are still largely available
Cost of rebuild is likely to go up w/ parts shortages/inflation
get an engine I won't have to worry about in the future if I do the rebuild right and address all the known failure points
Cons of doing a rebuild now:
Could I have driven the car for another 20k - 30k miles before having to rebuild? Perhaps more?
out of pocket expense (figuring somewhere between $20k and $30k) is a lot to stomach at once
not a lot go trustworthy options for a rebuild if you're not going to (or capable of) doing it yourself
the trustworthy guys have a decent backlog and are not cheap
There are probably points more but you get the idea. Anyone can look at this list and judge what can I live with and how much risk am I willing to swallow? The answer is not likely going to be the same for everyone.
In my case, I want to keep my car (I really do love it!). I am in line w/ one of the rebuilders awaiting an opportunity to get a slot. I have identified a local shop who can do all the work (trained at FSI) to remove and reinstall the engine after it is rebuilt. I have the cash set aside. I am driving the car and willl continue to do so until either my number comes up or I get piston knock. At that point it'll go into the garage until the engine can get rebuilt. Good luck! Whatever you decide to do, I hope you have a good outcome!
Wow, thanks for sharing. Those pics to my untrained eye look like very light scuff marks to me which maybe explains why your oil consumption is not high at all really (1 qt per 4K miles), as the manual quotes even 1qt per 384 miles is within acceptable limits. If I were you, I’d not even get on a list as I think your engine (barring any piston slap or sudden high oil usage) could go on for a way long time without issue. All engines wear from day 1. As for parts becoming more scarce, how do owners of old *** 911s from the 60s or 70s get their engines rebuilt when needed? There’s gotta be a way to still get engine parts for the 997 10, 20 yrs down the road still, and maybe there will be even more options made available for the consumer. I even read in a FB group I follow today that Hartech was going to start sending their cylinders to select shops in North America so that they could use their parts to do rebuilds. If I ever need to do a rebuild, I think there will be more choices out there and that’s a good thing.
I forgot to add that those pics were taken from the top of the cylinder. What the bottoms look like is an unknown. Could be worse, could be the same. Indy said it was scoring and I’ve gotten other folks w/ experience to look at them and they agree. Now there is a bit of self-interest in that the folks who see this the most are the ones who fix it, so take it for what it is. I also have seen the oil consumption increase to about 1 quart/2k miles. I also see the metals in my UOL, so not just going off the pics.
The one thing to note is that if you shorten the oil change interval you will definitely see a reduction in wear metals. But you have to factor in that since the oil was in for fewer miles, there will be less wear. So it’s important to normalize those two results to get a true view of the trends.
Last edited by 8KaboveMSL; 09-17-2022 at 09:59 AM.
I spoke to a few specialist today, they say all 3,8 engines after 100k km will have some sort of wear and tear in the cylinders. It is a none issue and a rebuild is not recommended. One said we can change the sleeves for 750 CDN a sleeve + the needed hours.
Based on the pics you are really early scoring, about where I was. The issue I ran into that made me check was I started to get a noticeable piston slap. I was lucky enough to snag a spot at FSI last year and took it. When the engine was torn down there was no noticeable scoring only the streaking you have pictured. What we did see was the coating on the pistons were starting to wear which is what FSI indicated caused the piston slap. The slap went away after an oil change to Castrol 5W40 and may have stayed away, but I was already in the FSI program. TBH had the noise resolved I probably could have driven another 10-20k before I noticed a major issue. That said it was going to eventually score, it was just a matter of time and I am stoked about the 4.0, so I have zero regrets.
I would absolutely not go the route you are suggesting on a fix though. These engines are difficult to build right and I would find a builder who can do it proper.
I bought a scope and it oil change time, actually a few month past the recommended 6 month OCI, and I'm going back and forth about whether to scope it. No oil consumption, first and only UOA in my ownership was fine save for slightly higher fuel dilution, tail pipes not sooty, but I do have a light scattering of what I assume are oil droplets on the bright yellow rear bumper that are visible upon close inspection. So, I am assuming it's there, I guess I really just want to know (or think I want to know) how much time I have. I've come to terms with the likelihood of scoring, so maybe let sleeping dogs lie. Ignorance is bliss, right? But then again, it's not really ignorance since I'm sure its there, and to ignore it would be kind of negligent (no offense to those who choose this route). I'm just curious what my timeline looks like. A $25K engine rebuild would be a major fork in the road for me. I believe it was Shakespeare who wrote, "To scope or not to scope: that is the question: Whether 'tis nobler in the mind to suffer the slings and arrows of outrageous fortune, or to take arms against a sea of troubles".
Originally Posted by Carreralicious
....I even read in a FB group I follow today that Hartech was going to start sending their cylinders to select shops in North America so that they could use their parts to do rebuilds…
Hope to hear more about this in the future.
Last edited by TerrestrialFlyte; 09-17-2022 at 11:04 AM.
I also have seen the oil consumption increase to about 1 quart/2k miles. I also see the metals in my UOL, so not just going off the pics.
Would love to see what your wear metals look like in conjunction with the current oil consumption. I believe that it's silicone and aluminum that are the main indicators.
Speaking with one shop re. oil consumption, they have seen cars with stuck piston rings with some hard carbon buildup causing significant blow-by and having the oil burned up. Basically a byproduct of previous owners not driving the car enough combined with annual oil changes and sometimes poor gas quality. This stuff really compounds over time. Once our cars have seen such treatment for 15 years no amount of oil changes or specific oil brands will fix this. From their experience, cars that have seen track time and lots of high revs rarely had these issues. This was combined with much more frequent oil changes.
Would love to see what your wear metals look like in conjunction with the current oil consumption. I believe that it's silicone and aluminum that are the main indicators.
I will post my Blackstone UOAs when I get the results of my latest one (w/DT 40) back. Should have it shortly.
Would love to see what your wear metals look like in conjunction with the current oil consumption. I believe that it's silicone and aluminum that are the main indicators.
Bore scoring is indicated by increased iron, aluminum, and silicon levels.
If you test your oil regularly, you'll have trend data for what is normal for your engine. When you see a change in wear metals or the rate at which the anti-wear additives are consumed, that's an indicator that there is a problem with the engine.
It's almost an instinct with me when I see bore score in the topic, I gotta look! Granted this one is from 2 years ago, but these days you can pickup a borescope for $20 on amazon and do the work yourself when changing your spark plugs.
Charles Navarro brings up an interesting point though, I always assumed if you see bore scoring it's definitive, you have it. But is it possible that oil lab results are more definitive and that just because you see scoring doesn't necessarily mean you're getting oil consumption?
09-16-2022, 05:52 PM
