Charles Navarro

Yup, bore scopes don't lie. Even with the 2009 and later models with the MA1/9A1 engine, bore scoring is indeed an issue. The 997.2 and 987.2 as well as the 991.1 and 981 also are susceptible to bore scoring. That is why these models all need to be bore scoped for scoring.


It is not until the 991.2 and 718 that bore scoring becomes a non-issue. These models have SUMEbore APS coated cylinder walls which should make them impervious to bore scoring.

andy7777

Why don't you just say what percentage of cars you have seen that suffer from bore scoring instead of marketing this ad for your services? Surely your shop knows. While you're at it, why don't you tell owners how many symptomless cars you have seen that turned out to have bore scoring. Suggesting that all 3.4 engines cars do a bore scope regardless of symptoms or history of usage doesn't serve the community very well.

Charles Navarro

Sorry, I can't give a hard percentage or number. If I did, it would be made up. We do not service cars either. The only blocks we see are those that are sent to us. I'd probably say somewhere around 5-10% of the blocks in 2023 were MA1/9A1 and they were all 3.4 or 3.8s.

What I can tell you is that most shops at this point are still using factory shortblocks for the MA1 engines since they are relatively inexpensive. This allows shops to do the repairs very quickly. Plus there are still many shops reluctant to rebuild these newer watercooled engines and using a factory shortblock simplifies things.

Not bore scoping any car that potentially could have bore scoring as part of a PPI is foolish. I've seen or heard of plenty of cars with zero symptoms that had bore scoring when scoped. I won't change my stance on this.

If you already own one of these cars, there really isn't any reason to scope it unless you want to. Used oil analysis is easier and is equally accurate in detecting even early scoring.

SeanPatrick31

@Charles Navarro Thank you for all that you do for the Porsche enthusiast community. You mention the 718 above as being free of potential scoring due to the SUMEbore coating. Do you have a view on the 718 non-turbo engines? In particular the GTS 4.0 and the GT4 engines (not the 2016 GT4 as that I understand can score)?

Thanks.

Charles Navarro

If it's an MA2 engine with a plastic oil pan then it has SUMEbore coated bores. I honestly don't know when this changeover occurred.

mccahey

You mentioned Oil Analysis, what are we looking for and have you any values that may concern you.

Charles Navarro

When I look at a report I am primarily looking at increased aluminum and silicon levels, however there typically also is an increase in iron levels as well to go along with it.

Typically when an engine is hurt the anti-wear additives will also be depleted and once ring seal is compromised we will often see increased fuel dilution as well.

It is best to have multiple test results from the same engine so you can generate trend data. It's only then when you see the valves deviate from the norm that you know you have a potential issue.

The problem I see if most people use Blackstone. That's fine and dandy but you get what you pay for. The commentary is worthless as are their universal averages, as least with what I have seen on Porsche customer reports. They use the ICP process whereas Speediagnostix uses the RDE which has twice the resolution (that's why you can't compare reports between the two labs).

SDX also does a dedicated GC test for actual fuel dilution rather than provide an estimated value based on flash point. SDX also does an oxidation test which is a better measure of oil life than the optional TBN test Blackstone offers.

Yes, I know it's a bunch more money than Blackstone, but at least you have Lake Speed Jr. himself reviewing the results and available to ask questions and to me, that's worth the extra money.

8Lug

Regarding soot on tailpipe, don’t 911s have the exhaust cross over? So bank 2 (passenger side) would exit through the drivers side tail pipe?

Charles Navarro

Correct, when the driver side tailpipe is sooty and the passenger isn't, then that's typically a red flag.

8Lug

The LN Engineering above states that on a Boxster or Cayman, it would be the passenger side getting sooty first. But isn’t bank 2 on a Cayman on the driver’s side, and not having crossover exhaust, that would also result in the drivers side tailpipe showing soot?

Charles Navarro

My apologies. I didn't notice this was on a 987 thread, so no crossover but the engine indeed is flipped in comparison to the 996/997, so I would still expect the drivers side to soot if the tips are not merged.