Percentage of M9X engines with borescoring?

The Mezgers didn't have the problem so are there any stats as to what percentage of M9X engines that had the borescoring problem? Thanks.

Man�. You�re going to get a bunch of random numbers.

I have a 2004 c4s. And it�s running great. I�m definitely paranoid about this topic. I can�t tell if LN engineering spends so much time talking about it because they are a business looking to make a buck or what. from what I gather. The materials used to make the cylinders is prone to the scoring. I do believe if the cars are taken care of properly and oil changed frequently (2-3 times a year) and the hot cold cycles are minimized it is entirely possible to keep significant scoring to a minimum. These cars are all over the place being driven like stink. From what I can tell not many have needed re sleaving or engine replacement, especially if cared for properly. I have not had my bores scoped. I honestly don�t want to know. I am using the driven oil for what it�s worth now. It runs fantastic. I only run it in the warmer times of year. Never in sub 45 Fahrenheit. i feel like once you scope it it�s a slippery slope from there. You either find it and never sleep a wink again. Find it and then fix it. Or find it. Pretend you didn�t see it and sell it ( which would not go well if done within the community unless advertised as such ). Anybody buying a 996/997 would best be served getting the bore scope done as part of PPI.

69%

Before and during my 2002 C4S plug and coil pack replacement, I had great plans to at least shoot top of piston shots looking for scoring. It stretched over several days, of finding time, here and there, to remove bumper, cheek mufflers, etc. aches and pains, of lying on my back, finding wrench to remove muffler bracket; it morphed into a different process of getting car back together and running properly. She runs so much better, with all coils working, but still a mystery as to whether there’s scoring or not. Guess I could drop oil pan and look below pistons. Remembering the time I arbitrarily dropped my BMW Airhead oil pan and discovered timing chain master link clip in bottom. No telling how long that chain stayed together without the clip! Guess one has to be careful what you look for, you might find something!

37.6%

0%�according to Porsche 😜

100% of engines where the owner follows the 20k mile oil change, doesn't keep the parts fresh and only drives the car a couple of miles to and from the grocery store every couple of weeks. 0% of engines where the owner changes the oil a couple of times a year, keeps the parts fresh and drives the car for at least 30 min stints to get it good and hot and an occasional track day. *while these are tongue in cheek estimates, same can be said for any car running alusil engines including other Porsches, BMWs, Audi, etc. You gotta service it right and drive it right.

100%, eventually.

Depends who you ask but it's anywhere from 0% to 100%. If you talk to a place that rebuilds they will give you a pretty high number since that's all they see.

Of the 997 cars I see, the sample of bore scored engines is 50%.

420%

It's nowhere near as bad as some particular people claim. I've read 8% but the excerpt below claims around 5%. Porsche GB advise that it sold 9,710 996s and 997s in the model years 2004-2006. Some very wet-finger-in-*the-air guesswork suggests independent specialist rebuilds and OPC warranty replacements combined may have reached 500 engines from that period, which indicates an overall percentage of around five per cent. excerpt: GT Porsche Magazine M96_M97_GTPorsche-Cylinder-Bore-Scoring.pdf (rpmspecialistcars.co.uk) Yes, mine was a victim of bore scoring but I was searching for one in that condition.... Don't let people scare you... Same with the IMS bearing. Mine was perfect with 83k on it.

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****in hippies. Heard the hippies 690% more likely to develop bore scoring cause of their lackluster maintenance schedules and driving around like pussies. Just see gc996 post above - if you perform maintenance and drive like your ***** have hair on them, impossible to develop bore scoring, literally impossible.

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Makes sense. Thanks for article.

I took apart a 3.6 with 102K miles. Not much scoring, so I dunked the whole case in PurplePower to give me a reason why I was in there in the first place. 🤣 Now I have a 4.0 with Nickies.

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The quote says 5% being replaced and/or warranteed. There are a number of cars that are running around with bore-scores that have not yet been detected, reported, rebuilt, or owners don't want to know. Let's say another 5%. That means 10% of 997 2004-2006 models have a single mode of failure of borescoring. I don't know about you, but any design that has 10% failure due to a single failure mode is actually pretty bad. Certainly not five 9's reliability. Don't be scared, but do be well informed.

I would go as far as to say that their are a bunch of cars tooling around with not only bore scoring, but also an imsb in the process of failing as well as their aos and water pumps failing. Let hope these guys get their cars serviced soon.

Just buy a Turbo.

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I love the turbo but it has the same issue as the M96 powered 996. The issue is the previous owners and if they properly serviced the car or not. Buyer beware on any 20+ year old car. This us why you need to buy one with a service history to see what has been done and when, as well as perform an invasive PPI to prove its in great shape.

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An instant classic. 69% dumber than anything else I�ve read today.

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Karen, off the meds today?

Good one Gary 👍

I think zbomb has been huffing too much gold paint again. I�ll have to translate for him. The same issue the 996 turbo and non turbo engines have is that the previous owners have either properly maintained the car or not properly maintained the car. Not the same mechanical issues. poorly maintained turbo 996 can be just as disastrous for an unsuspecting new owner. The prices some of these turbos are demanding out there are very short sighted. They have folks believing the meztger engines are bullet proof despite years of abuse and neglect. Just not true. I wouldn�t want one without records, and pinned coolant lines.

My 2cents.... bore score is the final symptom of failing loco-sil cylinders, don't have to wait for bore score to get excess blowby, piston slap, and oil consumption and loss of hp. Taper/out of round, most of the time is a precursor of bore score in m96 engines. Out of round/taper is the real problem. that starts the cylinder down the bore score road. I Bore gauged a very clean 2002 996.2 3.6 at 60,000miles, just a little while ago, with the owner, an active forum member here. He is a meticulous guy that maintains his car better than good. He uses DT40. My take away from this bore gauge check,,,, cyls can look perfect with no score what so ever. Not even the smallest sign of wear. But measured at .0025"+ taper average on most cyl. Maybe 1 cyl went up to . 0027". Been said on our forum in the past, . 003 is max out of round/taper limit . In many other engines, .002" is max taper/out of round. So at 60,000 miles on a meticulously maintained engine, the block is almost out of spec. Probably the remaining piston coating would be gone by 80,000 resulting in heavy bore score from the taper/out of round. So, IMO, what experts have explained in detail, the cyl structure is faulty. Correct me if I'm wrong, but what I've gathered here from the engine experts, the defective loco-sil materiel that is 1/4" thick lining the cyls collapses/changes internally(?) or on a molecular level, more or less causing out of round/taper. Now maybe poor maintenance will speed things up, but doesn't seem to matter what you do, by 80-100,000 miles block is probably shot and maybe been that way for half its life... One of the largest expert Porsche engine builders have told us in the forum that by 100,000 miles most all 996 cyls will be over max out of round, and some by a huge amount. Whats much more important in my opinion than " % of engines with bore scoring" is the 100% of engines that have/will have out of round/taper thats the cause/harbinger of dreaded bore score... Yup, once that piston starts slapping around in its out of round cyl, not long before all the ferrous piston coating wears off and aluminum on loco-sil starts to score the crap out of the cyl walls... Some say bore score is not that critical, depending on its severity... Suppose thats up to the individual owner to decide. Both my 996 have around 35,000 miles and burn no oil between changes. No piston slap noise, no smoke belching out of my exhaust, no constantly making sure oil level isn't critically low, no loss in compression/power. I know once the miles double, out of round will probably be there at max limit. Maybe not enough to cause any problems yet but it won't be long. Not sure if I could enjoy a high end sports car that does/has all of the above. Eventually all the grit/debris/piston slap from bore score will cause engine failure... So to all of us 996 owners, just know this and plan accordingly.... jmho

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It's all good data points to have. Never seen that article before, but those numbers are in line with what some of our Porsche dealership customers had relayed to me with regards to how many engines they were replacing a month around the time that article was put out. At least it's pretty easy to scope the cylinders and take action to mitigate this issue.

Yep, and pretty easy to test the oil as well. Not to mention mitigate IMSB, AOS and water pump failure.

Just compare the maintenance life of a 996 to a Apprillia race bike.. Then it kinda makes sense..

The beauty of the M9X is that is benefits from 20+ years of failure analysis and private sector solutions. We have choices on which �correction� we want to use in many cases. In my eyes, this alone makes the platform the least risky to own. I see videos of the latest and greatest engines from Porsche and shudder to think of owning one of those. They have a lot more parts, are more expensive and have less development. AND they fail for many of the same reasons as the M9X along with their own special failures. As an enthusiast, that does not interest me.

Its not talked about much, but the V engines in the Sport utilities from Porsche have their bore issues as well.. Same reasons, too much time on the oil, fouled injectors washing down the cylinder walls, coating failures...

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Total nonsense...wow

�better the devil you know�

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Amen brother. And after 20+ years, we know it well.

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100% Agreement. The issues are so thoroughly documented and the solutions available, that I bought my 2002 Cab sight unseen from a Porsche dealer. The original owner had it 19 years, it had a well documented service history, the dealer gave me its own inspection report (which got some things right that needed repair) and the price began with a 2. I have been buying used German cars for years and this was both my first Porsche and my first sight-unseen buy, but I had confidence that there wasn't anything I didn't know in advance because its "flaws" have been so endlessly documented. And I drive it like I drove my Ducati 748.

My two bits - It’s an M9X non-Mezger engine. “The devil you know…” applies. Have a plan. Budget for the plan. Execute the plan. Drive the car with the right foot down as often as possible. Service the car. Repeat.

Well, that didn't get me anywhere. For some reason I thought I had seen an actual percentage of cars that were estimated with BSing. My opinion is that over 80 percent of cars have BSing or would have it if introduced to colder climates. I don't think all BSing is catastrophic however, and as long as it is managed properly, the engines are still mostly functional even after being diagnosed with BSing. There is no "Beuty" to this. IMO it was a massive "F"up by a manufacturer that should have known better, or mitigated it better. IMO the only reason they survived this with the IMS issue is because of owners that are willing to put up with it due to BRAND LOYALTY and I don't think many other companies with would have gotten away with it. But that is all just the opinion of a Regular Guy.

Google Mercedes borescoring as well as BMW. You will find the problem beyond Porsche. Something to do with environment laws. FSI was developing the Sumabore coating in case Niki coatings go away due to legislative changes.

So here is a more fundamental question. Why the coatings at all. In fact it is such a different question that I'm going to start a new thread on it.

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I believe Porsche started using Sumebore coatings in their motors starting with 991.2. Porsche first used SUMEbore with the 918 Spyder, providing added durability over Alusil and Lokasil. The SUMEbore coating is applied only .004� thick, just like Nikasil. However, it is applied using a high temperature spray on process that fuses the coating to the aluminum bore in a process that is much more environmentally friendly than plating. Other manufacturers similarly have used SUMEbore and other APS and PTWA cylinder bore coatings on their aluminum engine blocks for high performance engines, like those found in the Nissan GT-R and Ford Shelby GT500, in place of Nikasil coatings.