sandwedge

I don't know that there's a way to find an exact or even a close to exact number on this but your figures make sense. 10-20% would just be an impossible number of cars involved that would have made way more news both in main stream media and social media.

Chris M.

mjsporsche

Lets get real. Too much anxiety placed on this topic. As mentioned in an earlier post, bore scoring affects a number of Porsche models. And bore scoring is not limited to Porsche brand. And when the 991s start to accumulate miles and years, there will be something with those too.

Will it be a significant cost to repair when bore scoring happens? Sure. But I am not obsessed about it and rather just enjoy the drives. So if it is 1% or maybe 20% of possible failures, it does not mean much to me.

997_4me

This.
Have money set aside for any type of failure so when/if something happens you are well prepared. Another option is getting 3rd party insurance coverage. If the percentages of failure are still too high for comfort or you are constantly worried about it then get rid of the car and buy something that gives you peace of mine. I don't think twice about potential failures.

Ward1

DesmoSD

It would be very difficult to track how many 997.1 had bore scoring since there were some misdiagnosed and/or never reported issues (engine replacements). Keep in mind that it wasn't only 997.1 but also 996 and 987's. Each generation of 911's has had their own set of issue starting with the long hoods to the mid year impact bumper to 964 heads to the 996/997 Turbo and GT3 coolant leak. Even the 997.2's are now starting to report LSPI and bore scoring with faulty injectors. The newer models like GT4/GT3 are having numerous front suspension towers snapping and the 991.1 GT3 engine issue with a warranty valid until 2020.

Vincent713

According to what the experts are saying, I think one of the best preventative bore score from happening is to replace your fuel injectors if you have a 997 with over 40k miles. Yes it would be great if we can get a somewhat accurate numbers of bore scoring engines.

Flat_Six_

Did Jake or someone else specifically recommend this? I gleaned it from some conversations, but did not see this as specifically recommended as preventative maintenance.

Vincent713

I think it was Jake that mention about the injectors and instead of rebuilding them he recommends to replace them.

Chris M.

cannonball05

What is the ballpark cost of replacing injectors from an indy?

cwheeler

I think that was for the DFI engines.

I could be wrong tho.

Cw

laphan

LN Engineering has Bore-scoring preventative article on their facebook.
Here is what it says (I hope Charles is okay with me posting this, if not let me know and I will delete it):

Concerned about cylinder scoring? Here are a few things you can do to help lessen your chances of scoring:

1. Change your oil every 6 months or 5,000 miles with Driven DT40 on 1997-2008 models with the m96 or m97 engine and DI40 on 2009 and later models with the MA1 (9A1) engine.

If you do frequent short drives, you should change your oil every 3k miles or 3 months.

2. Use Top Tier fuels and Driven Injector Defender at least every 3,000 miles or better every fill up.

3. Install a low temperature thermostat.

4. In colder climates, once the engine gets off cold start, don’t idle the engine any more and start driving. Limit yourself to 50% throttle and keep the engine under 3,500 rpm until the engine is at full temperature.

5. Add used oil analysis to your toolbox. Scored cylinders typically will be visible in test results with elevated aluminum and silicon levels, often with reduced oil viscosity and increased fuel contamination.

Driven products and SPEEDiagnostix used oil analysis kits can be ordered from LN Engineering at:

https://lnengineering.com/…/joe-gibbs-racing-driven-product…

https://lnengineering.com/products/used-oil-analysis.html

Flat_Six_

Charles Navarro

I have no problem sharing this info. I am working closely with two individuals with early signs of scoring. Definitively, one of them has bank 2 enrichment issues, but we're still waiting of further diagnostics to be carried out on their end.

I'm in the process of scouring through dozens of whitepapers on hypereutectic block development and testing to see if I can find any corroborating evidence that might help us understand this scoring issue better.

One thing I did read that Mercury Marine uses a similar process called Mercosil, which is like Alusil, but it has graphite embedded in the bores, which acts like a solid lubricant. There is some tribological film forming on the bores that interacts with the hard silicon particles and softer aluminum and when the silicon is removed, the soft aluminum experiences abrasive wear.

I do know many people racing M96 and 9A1 engines with zero cylinder issues with years of track use and hundreds of hours, but they are all running Driven XP9, which has lots of moly.

We are all looking into the possibility of a different oil or maybe an additive that would work with DT40 or FR50 (Driven's 5w50) that might improve the load carrying capability of the lubricant and reduce the piston and cylinder wear that leads to these scoring events.

I'm spending all my free time day and night devoted to this as it's our number one concern right now.