Porsche 996 bore scoring symptoms pca. This week, my usual independent specialist has diagnosed suspected bore scoring - which, listening to confirmed examples on YouTube, sounds entirely correct. 1 uses Lokasil and bore scoring is a rare failure on all these engines. Jan 19, 2013 · After reading alot of posts about this subject and a few conversations with Porsche dealers it would appear that bore scoring is more prevalent in only some models? 3. Even early signs of scoring will show up as increased levels of iron, aluminum, and silicon. While there are more than a few cases of this problem on older engine designs, if you have a 9A1 motor there are very few examples that I have ever heard of. A low temp thermostat is supposed to help mitigate this. The problem seems to be solved by Porsche by the time they got to the 9A1 motors. Incidentally I spoke to an independent today that reckoned that Aug 24, 2023 · On a major service he asked the garage to borescope the car during the plug change- they found evidence of scoring in cylinders 5 and 6- but was described as light. The new engine, dubbed the M96, made more power than any It doesn’t help that Porsche Club NA has videos of people basically screaming that all 996 and 997. May 20, 2009 · Identifying bore scoring - photos Sold For Sale: 2002 PORSCHE 911 996. Now I have my eyes on a higher mileage 2008 Cayenne Turbo. 1 and . Bore scoring, like a lot of things that have low probability but high consequences, gets a lot of bandwidth on the internet. 03 The Porsche engines we most commonly see with cylinder bore scoring that are sent to us for repair include the M96. Subscribe: https://www. 4-litre. Mar 5, 2019 · Porsche 992: 2018- Porsche 991: 2011-2019 Porsche 997: 2004-2012 Porsche 996: 1997-2005 Porsche 993: 1993-1998 Porsche 964: 1989-1993 Porsche Carrera 3. 6K miles of short runs. The last one was under 20k. Although bore scoring on a 991. Simply put, it’s a 23 year old German sports car made in a period when the company wasn’t sure it would survive. To diagnose the issue I did a pressure down test at a shop, the worst side was on cylinder 4,5,6 (right/passenger). One of the symptoms described by Flat6 Innovations in their video series on the subject is a ticking noise at idle, a bit like a sticky hydraulic tappet, which they say never happens, or very rarely, on Mar 8, 2022 · The 996 and 997 Porsche models suffer from bore scoring. Replacing the legendary air-cooled, two-valve, single-overhead-camshaft flat-six was a water-cooled engine with double the valves and camshafts. The 997 3. This issue can cause the Porsche engine to Oct 11, 2022 · Bore score only affects the larger bore 3. 1 in terms of things to watch out for. Ive given up worrying now. If you have no symptoms, carrying out used oil analysis is the easiest way to evaluate the health of your engine. What is Porsche Cylinder Bore Scoring; How to Prevent Porsche Bore Scoring; Porsche Cylinder Bore Scoping; Porsche Bore Scoring Sound; Bore Scoring Repair Costs; Porsche Club of America Bore Scoring Info; Nickies Sleeving Process; Nikasil & NSC Cylinder Platings; IMS Dec 12, 2023 · Porsche had Le Mans-sized shoes to fill with its first fully-water-cooled 911 engine. I don’t believe the hype, but I’m also not in that market for different reasons other than bore scoring. 4 engine used in early 996, Cayman S, and late Boxster S models. The reason you’re finding it hard to find rollers with bore scoring is that people who find bore scoring offload or rebuild well before the symptoms get bad (which can take years) because it’s uncomfortable driving around with ticking and smoke and high oil consumption. 2 Carrera S 5 years ago and so a lot of 5 mile journeysalbeit in 5 years only c. Learn about the costs associated with repairing this issue, including Porsch The bottom line is that while we've seen perhaps 5% of the 2004-09 generation 1 cars we've inspected with the early warning signs of bore scoring, it isn't something you should avoid the model for. 1. IMS still affects 997. It is usually the right side cylinder bank that most easily gets scored (the right hand bank of cylinders appears less well cooled than the left). Learn what to do if you have scored bores in your Porsche. I live in Canada and I know cold weather is a factor on bore scoring on these vehicles. A diagnosis of scored bores doesn’t immediately mean your engine is dead. Mar 29, 2023 · Bore score can create soot, but I'd expect it to be oily and come with other symptoms (tick/knock sound as the engine runs, dirty oil, oil consumption, etc. Apr 19, 2023 · Cylinder bore scoring can cause engine damage in Porsche 911 996 and 997 models. 01 3. Look for signs of mixing (oil in coolant and/or coolant in oil), which would point you toward gaskets/cracks, and signs of coolant or oil loss. In the final segment, How to fix bore scoring in your Porsche’s M96/M97 engine, solutions to cylinder bore scoring in Porsche engines are discussed in detail, including LN Engineering’s Nickies cylinder sleeves which fix all known cylinder issues with the M96 and M97 engine – slipped sleeve, d-chunk, and cylinder bore scoring issues that Mar 27, 2017 · 997 Bore Scoring found upon inspection. So, what constitutes the ideal bore scoring service? First, you have to make sure that the technicians are qualified. Porsche Boxster/Cayman 986/987 ca 4 900 kr Nov 3, 2024 · Porsche M96/M97 Bore Scoring issues explainedThere are many articles online and various posts in Porsche forums about bore scoring issues and engine failure! While cylinder bore scoring has been an issue on a relatively small percentage of 996 and997 models, it isn’t a universal problem. But as these cars have gotten older, bore scoring is the number one failure we see, specifically 996 and 997 models. Owners of these cars aren't anywhere as passionate about their vehicles compared to owners of sports car models, so you don't often see them online or on the forums or even at Porsche events. Buyer Beware: The Reality of buying a “used low mileage engine”Lost Documentation InfoENGINE UPGRADESStocker On the contrary the most likely to score are the latest of the 996/7 (non GT3 or turbo) engines because they have bigger capacity, more forces pushing the pistons against the cylinder wall and a softer piston coating that cannot protect it as well. The same recommendations we make for the earlier cars to prevent cylinder bore scoring should be observed, including running an oil with high levels of moly friction modifiers such as DI40. There are many ways to help extend the life of these engines and that starts with giving your engine a clean bill of health with bore scoping the cylinders and doing used oil analysis. The Porsche engines we most commonly see with cylinder bore scoring that are sent to us for repair include the M96. The Porsche 997, introduced in 2004, continued the legacy of the 911 series with its sleek design and impressive driving dynamics. (2021 Edition)Part 3 of FOCUS ON: BORE SCORING begins the discussion on the "symptoms of bore scoring". 997. I had a 2008 Cayenne S previously and I loved that vehicle. Porsche 996 and 997 bore scoring is a well-documented issue that affects many water-cooled Porsche models, particularly the 996 (1999-2004) and 997 (2005-2008). 8 liter M96. Porsche Bore Scoring Fix And Symptoms How Much Does It Cost ??? For Business Contact :Nathan's Porsche WorkshopPo Box 115 Altenburg Mo 63732nathan. 6 in the 911 models) and is thought to be due to a hotspot developing on the wall of cylinder 6 (IIRC) before the water is fully circulating if the engine is not fully warmed up before being driven hard. Jan 21, 2020 · I recently watched a YouTube video on bore scoring and am now concerned that I have it. Online, the fear is REAL! If I were you, and you have the budget for 997. The statistic is lower than 10%. 03, M96. - Porsche AG The Janurary 2025 Issue of Panorama is online. The Porsche bore scoring issue is well known among owners, enthusiasts, and mechanics. The reporter outlined the analysis done by Barry Hart, the boss of Hartech who are the main Porsche engine rebuild specialists in the UK. 6 and M97. 4 Cayman/Boxster S engines also suffer from cylinder bore scoring. Bad bore scoring, piston slap and coolant in the oil. The right technical service has been recommended by peers or is known for its excellent reputation for working on cars of all types and makes. Porsche 996 bore scoring is quite common in the 3. 1 Carrera and Carrera S (Turbo and GT3 models excluded) May 4, 2023 · The simple truth is that while cylinder bore scoring has been an issue on a relatively small percentage of 996 and 997 models, it isn’t a universal problem. Have any members experienced similar, and how did the scoring progress? the garage advised he might not have issues for several years. 0 through 2. 2 Bore scoring Hi all, was looking to buy a 997. ). The Raby method makes sense but not without patience and experience with noodling a bore scope up from the bottom of the engine. Read from official statistics that only 3% of the vehicles had these problems. 2: 1983-1989 Porsche Carrera SC: 1977-1983 Porsche 930 Turbo: 1975-1989 Porsche Early 911: 1964-1977 Dec 6, 2022 · In this video i explain everything you need to know about Porsche bore scoring , what to look out for and what are the odds of your Porsche having this issue There has been more written on the bore scoring problems with Porsche 996 and 997 engines than you can probably fit in the Library of Congress. Porsche 911 – 997 (2009 – 2012) ca 4 900 kr. Its a remote out of state purchase and despite all the service history etc looking good I am reading up a lot about borescore and not finding any conclusive information It seems this engine type can have bore score,. I have a 996. 4 and 3. Here's our score on bore score and how to avoid it. com/watch?v=8T6GxOoezhsWhen I started this proje May 17, 2024 · Identifying the Porsche Bore Scoring Problem The audible Porsche Bore Scoring Sound (Tick) is the earliest indicator that your engine might have cylinder bore scoring, even before any other symptoms are present. 2 Bore scoring - Hi All, I am soon to pull the plug on a low mileage boxster S 987. 996/997 GT3 & Turbo; Porsche 944/944T/968; Porsche Cylinder Bore Scoring. 4 M97. Porsche models from 1997 through 2008 including the 911, 996, and 997 as well as the Boxster, Cayman, 986, and 987 have all can experience the Porsche bore scoring problem. The 3. So take it all with a grain of salt. 01 engines and Porsche Cayman cylinder bore scoring in 3. Ive fitted the lower temp stat. Why does the 996 deserve all the bad press for a rare failure? 996/997 GT3 & Turbo; Porsche 944/944T/968; The symptoms of cylinder bore scoring may not be immediately apparent, but they will become more noticeable over time A PPI that doesn’t drop the oil pan won’t catch early bore scoring. 21 engines are most common; below are all the models with M96 or M97 engines that can experience this issue: Feb 8, 2024 · There has been more written on the bore scoring problems with Porsche 996 and 997 engines than you can probably fit in the Library of Congress. IMS - Intermediate Shaft The crankshaft indirectly drives the camshafts via the aptly named intermediate shaft. Find our more about symptoms and recommendations on the following service page . Bore scoring always results in complete engine disassembly, so it is not a cheap problem to fix. (5) Valve seats. I mean, who posts every few months that their car has not experienced bore scoring. Good news I say? Well, yes - because engine rebuilds are exciting and means I can get it rebuilt to my specification in the knowledge that it (shouldn't!) explode o Nov 23, 2024 · HOMERESOURCESMediaWarrantyThe Flat 6 DifferenceMost common M96/97 engine failure modesCylinder Bore (Scoring)Excessive oil consumptionSpare Parts and Broken Hearts- The tale of a bad decision. Bore scorring issues explained and tell tail signs. The process will confir Jun 29, 2021 · Cylinder Scoring Symptoms. Jun 18, 2021 · The motor in my Porsche 987 Special Design 2 is a 3. 2007 Cayman S listed for sale after bore scoring was found. All water cooled 911’s Boxster’s and Caymans from 2004 through to 2006 are at risk of suffering from bore scoring however, it would appear the percentage of engines actually affected is relatively low. 2: Lack of bank specific pistons has been suggested as a contributing factor to bore scoring in Porsche Boxster, Cayman, and 911 models. 6 and 3. 8liter engine and even I know the ideal buy may be the 2010 where the bore scoring is not the issue, the examples I can find are out of my budget. 6 liter engines. It affects the Cayennes and Macans too. This part of the bore scoring series will be divided Apr 19, 2007 · 2007 SC, Bi Xenon, roof rack, red tail light option, Ohlins R&T, Tarett Cup Race LCA's f&r, Tarett GT sway bars, down links, Elephant toe & bump steer links f&r, r toe locker plates, f slotted frame camber mounts, Pedro's r TechnoBrace, Racing Dynamics f strut brace, Function First orange motor mount insert & tranny mounts, Numeric short Unfortunately, many Boxster, Cayman, 911, Cayenne, Panamera, and Macan engines will still suffer cylinder bore scoring. 996. 05, and M97. 2 and later sports car engines, so no need to worry about bore scoring on those models as it pertains to models with Alusil and Lokasil engine blocks. It can also be caused by coolant leaking into the engine oil or by parts of the engine wearing down and leaving metal particles in the oil. However, there are some tell tell symptoms that indicate your engine may be suffering from cylinder bore scoring that include: Audible Tick; Increase in Oil Consumption; Sooty Tailpipes ; Soot in the Engine Oil; Oily/Sooty Oct 4, 2017 · Find out why bore scoring happens and what you can do to help prevent engine failure. Porsche went to SUMEbore for the 718 and 991. 1 is rare, it does happen, and as the cars get older, we are seeing more instances of scoring and piston seizing. 4 996 The 3. 4 liter 911 models. 05 3. Yes, bore scoring is indeed a thing with Panamera and Macan models like it is in a Cayenne. 8 engines as well as the 987 3. How does bor Mar 8, 2011 · The damage seems to take some time to gradually get worse and initially can be present with no symptoms at all "" gradually increasing oil consumption and slightly less sharp performance (that many owners do not notice until they receive a rebuilt engine back and remember how crisp it used to be). Go . 1 C4S is suffering from bore scoring on cylinders 5 & 6. 22 3. 2 3. WHAT IS BORE SCORING? PORSCHE 996 & 997 (Episode 25)Want to see how all this started? 😃 https://www. All day. We are seeing this on low mile 997. youtube. youtube@ya Owners of Porsche Boxster, Cayman, or 911 models with the M96 or M97 engine know bore scoring is a real problem. 7 engines used in Porsche Boxster models and the base 2. If you look at the photo gallery below, you will see typical wear and light scoring found in almost every car on the road. 2 and 991. Apr 15, 2019 · Where other shops fall short,, Jake Raby shows you where scoring starts by using a technique that he developed at Flat 6 Innovations. Be a smart buyer like me and buy 987/997 higher mileage example (80-110K miles) and as part of PPI get Bore Scope Inspection thru spark plug holes when Below are all the models that need to be bore scoped for cylinder bore scoring: Porsche 996 bore scoping are obvious symptoms such as sooty tail pipes, piston Bore Scoring, 997 Bouncing between a 997 S and a 987, ideally would love to be in the Carerra S to simply have the extra seat for my 6yr old. 8 engine. Bore scoring can affect the engine’s performance and longevity if not addressed promptly. Got rid of it, got an X5 but I miss the Cayenne. My almost mint 996 C2 (52 plate with 40k miles) was recently diagnosed with some bore scoring on two cylinders. Dec 21, 2024 · What are Porsche cylinders made of? Although biral cylinders are a significant upgrade over cast iron cylinders, Porsche started using solid aluminum cylinders all the way back in 1951 in its production cars, before cast iron and later biral-type cylinders were first used on later Porsche 356 and 912 models followed by 2. IMS bearing showed no symptoms. 1's. Mar 26, 2022 · My pride and joy 2003 996 Carrera 2 developed an increasingly unhealthy sounding loud ticking noise and recently started using more oil than usual. Porsche models from 1997 through 2008 including the 911, 996, and 997 as well as the Boxster, Cayman, 986, and 987 have all experienced the Porsche bore scoring problem. A complete engine disassembly is required for repairing cylinder bore scoring, and the repair cost for fixing Porsche 911 996 and 997 engine blocks with cylinder bore scoring ranges from $5000 to $6000. Feb 11, 2021 · We perform a good number of PPI's and have run into a substantial number of 997. Bore scoring can affect any engine with Lokasil or Alusil engine blocks, so that would indeed include the 997. org-----------------------------------------You may have hea Actually all “non Mezger” Porsche engines up to the 991. What about the bore scoring and IMS failures with the 996/Boxster?” Well, despite being air-cooled specialists, we do get asked that a lot too. I had bore scoring, the ticking sound is from the piston slapping the cylinder wall. 2 and the early 3. I moved to 997. A PPI that doesn’t pull the plugs won’t catch moderate to advanced bore scoring. 4 engine fitted to Porsche Cayman S and Boxster S vehicles is also susceptible to bore scoring. 7L) anecdotally experience the least bore scoring. They utilize the same Alusil technology for the engine blocks. Sep 29, 2014 · Hi, Ive just recently bought a 1998 996 and was worried about the same issues. 4 engine used in Cayman S and late Boxster S models. Porsche models from 1997 through 2008 including the 911, 996, and 997 as well as the Boxster, Cayman, 986, and 987 have all experienced the Porsche IMS bearing problem. Sep 8, 2024 · Car Info and Introduction: Year: 2004 Model: Carrera 4S Milage: 62,000 Miles Miles Since Last Oil Change: 4000mi Oil: Motul 8100 X-Cess Gen 2 5w40 Additives: 2 Bottles LubroMoly Ceratec Modifications: Low-Temp Thermostat, Magnetic Drain Plug, Rennline Tunable Semi-Solid Engine Mounts, LN Dec 18, 2024 · 996 - IMS failures & Bore Scoring 997 - Small % Bore ScoringSo considering Porsche history, I doubt there would be any chance having Porsche open their pocketbook on the Bore Scoring issues. Preventing cylinder bore scoring starts with determining if your engine already has bore scoring. The car I looked at had a water pump failure on the motorway which raised my suspicions about a potential problem. Bore scoring is most common in Porsche 911 vehicles, including 996 and 997 models, fitted with the 3. 1's with cylinder bore scoring. 2 and 997 engines as well as with the M97. He does around 3000 miles a year. Below are all the models that need to be bore scoped for cylinder bore scoring: Porsche 996 bore scoping ; Porsche 997 bore scoping Jan 20, 2022 · For those who missed it, follow this link to view the video of Tuesday evening’s presentation by the Hartech team which discussed in detail IMS bearing and bore scoring issues - and more - on the 996 and Gen1 987/997. 5 and 2. Certain Porsche models are more susceptible than others to Porsche cylinder bore scoring. 22 engine used in 2007-2008 Boxster S models is also very common, so having any of these engines bore scoped is a must. Sep 23, 2022 · The right technical service can fix your bore-scoring problem. Porsche IMS Bearing Problems (And How To Fix Them) The Porsche IMS bearing issue is well known among owners, enthusiasts, and mechanics. Cylinder #4 was toast. 1 day ago · The Porsche engines we most commonly see with cylinder bore scoring that are sent to us for repair include the 3. Jan 9, 2025 · Raby has always said the beginning stage of bore scoring is the loss of piston skirt material but when it comes to the cylinders, bore scoring begins at BDC at change-over on the thrust side of the piston. 0. Apr 8, 2017 · Interesting article in 911 & Porsche World (May 2017 issue) regarding bore scoring in MA1 engines. He believes and it makes common sense that a large contributor is leaking fuel injectors . Bore scoring is a problem that is commonly caused by oil that is not up to the job. 1 is the less probable to have problems. Bore scoring applies to both . 03/M96. How does bore scoring happen? Due to the layout of the open deck crankcase on 996/997 models, the cylinder banks are not rigidly supported like the first generation 928, 944 & 968 watercooled engines. The scoring seems worse on bank 2, (cyl's 4,5 & 6), and often carbons up the left tailpipe tip. org-----You may have hea 2004 Porsche 996 C4S. Bore score and IMS failure is always on my mind to be honest, no matter what statistic I tell myself, I always #flatsix #borescope #996bores #borescoring #porschelove #porsche911 #porsche997carrera #borescoringpreventionThis video is inspired by a interesting comment Bore scoring , ims and rms are the main problems in 911 (1998-2007). 21/M97. 4 (and 3. One exhaust pipe is coated in black soot; The engine making a knocking noise that resembles a hydraulic lift; Increase in oil consumption; Porsche M97 Cylinder Scoring Repair Options . All Porsche Boxster, Cayman, and 911 996 and 997 vehicles from 1997 through 2008 with the M96 or M97 engine have an intermediate shaft that is supported by the Porsche IMS bearing. As one of the most concerning engine issues for Porsche owners, it’s crucial to understand its causes, how to prevent it, and what optio Porsche bore scoring: How common is it? Bore Scoring for Porsche Although it has affected a relatively limited number of 996 and 997 vehicles, cylinder bore scoring isn’t a constant concern. I was under the impression that when bore scoring was evident that engine demise was close. I am hearing of more such engines with Lokasil cylinder liners being afflicted by bore scoring. How can you stop the Porsche 987’s bore score? Use a bottle of Driven Injector Defender every other fill-up to maintain your fuel injectors. 4 liter M96. Jun 9, 2022 · Porsche engines with Lokasil or Alusil engine blocks can suffer from cylinder bore scoring. Engine use to run at 92-98+ degrees. Fuel tends to puddle in the cylinders because they are horizontal . However, like any complex machinery, the 997 is not immune to issues, one of the most notable being bore scoring. Dec 15, 2024 · 987 Forum - 987. if you were to examine the bores on lots of apparently healthy 911's that you The Porsche engines most commonly diagnosed with cylinder bore scoring include the 3. 1 with a trashed engine, and du a Hartech rebuild (UK Based specialist). 2. Is this a concern Jake Raby shares with us an in-depth account of a Porsche M96 engine that has failed due to “Bor **PLEASE SUBSCRIBE**From the Morgue at Flat 6 Innovations Apr 5, 2013 · Its interesting that Hartech has advised a way to manage the bore scoring. Porsche 911 – 997 (2005 – 2008) ca 4 900 kr. IMS Bearing Kits. 01/02/04 engine found in 99-01 Porsche 911 996 models indeed do suffer less from bore scoring, but we do see some with slipped sleeves and d-chunk failures, the latter failure mode being very uncommon in later 996 and 997 models. Like anyone about to crack into a Make/model, went to youtube to fain insight potential issues and maintenance worth noting. What are the symptoms of Porsche Bore Scoring? There are many contributing factors to the Porsche bore scoring issue. Om din bil skulle vara drabbad av bore scoring kan vi självklart hjälpa till med åtgärd och renovering av motorn. Porsche 911 996 and 997 cylinder bore scoring in 3. As with any Porsche, it's a must to have a proper PPI carried out which would include bore scoping the cylinders and even doing used oil analysis. While cylinder bore scoring has been an issue on a relatively small percentage of 996 and 997 models, it isn’t a universal problem. 7 engine used in the Porsche Cayman do not often suffer from cylinder bore scoring. The Definitive Guide and FAQ for Porsche IMS Bearings. The engines we most commonly see with bore scoring that are sent to us for repair include the 3. While speaking with the guy about the cost (£12-16k if you are curious) I obviously asked if i was better off with a 2nd gen. 6 C2 MANUAL Davidmudley; 9 Feb 2023; Porsche 911 Water-cooled CARS For Sale & Wanted; Mar 15, 2013 · I suffered bore score on my 997. Dec 7, 2022 · In general, the "base" engine cars (2. Before rebuilding the engine, I was consuming one quart of oil (1l) per 800 km. Mar 30, 2023 · You may have heard of cylinder bore scoring as it relates to the Porsche 911, Boxster, or Cayman built for the 1999-2008 model years, but chances are you don't know the full story. Bore scoring in the 2006-2008 3. 21 Porsche Cayman engine as well as in the 3. 8 Porsche 911 996 and 997 engines as well as with the 3. Nov 6, 2024 · The Porsche bore scoring issue is well known among owners, enthusiasts, and mechanics. Rebuilding to a 4. Bore Scoring Unlike the base and S Porsche 911 996 and 997 models, the base 2. 2004-2012 Porsche 996: 1997-2005 Porsche 993: 1993-1998 Porsche 964: 1989-1993 Porsche Carrera 3. Many of them run well, and some have a ticking sound as a tell-tale. Until I realized I bought it already with a pretty serious case of cylinder scoring. Jun 10, 2024 · I'm on the market for a 911 (997) 2005-2008 with preferrably 3. FACT #1: Cylinder Bore Scoring is the #1 leading cause of misdiagnosed engine failures for the following vehicles: 1999-2004 Porsche 996 (all models except GT3 and Turbo, less prominent with 99-01 years, but still occurs) 2005-2008 Porsche 997. Oct 6, 2015 · Good evening, So today I got given the good news that my 2007 plate 997. 1’s WILL have bore scoring at some point in their life. Priser kontroll av bore scoring: Porsche 911 – 996 (1998 – 2005) ca 4 900 kr. com/porscheclubofamerica?sub_confirmation=1Visit: https://www. As I understand it, only a small percentage run into this catastrophic fate - but f I'm among them, what's my best response? It's essential to maintain your engine properly to minimize the chances of cylinder bore scoring, but if your Porsche 911 996 or 997 engine does have a bore scoring failure, LN Engineering’s Nickies sleeves are the permanent solution to this problem. 8 Porsche 911 996 and 997 en Unfortunately, many Boxster, Cayman, 911, Cayenne, Panamera, and Macan engines with Alusil or Lokasil engine blocks will suffer cylinder bore scoring. 2 which is very similar to the 997. 8 Porsche 911 996. 2, but like you said, affected number is unknown and likely difficult since bore scoring symptoms can be dragged out for a while before catastrophic failure. I am doing some maintenance and got myself a borescope to have a look and was surprised to find the attached. I have yet to hear of a problem with a 991. Bore scoring is a growing concern for these engines per Jake Raby . sqqa gorh jqngc iktwr lmn ipvle uccan piv ubxapk qwqaa