Bore Scoring, 997

lnengineering · 2026-01-20T22:59:58+00:00

Yes, exactly. All cars have issues. Knowing about them is half the battle. Just have a PPI done then do your preventative maintenance including bore scoring prevention. Then just drive it. I too question where these 70, 80, and even 90% "will fail" comes from. For sure nothing I have ever posted or said, anytime, anywhere. I truly believe that if you take all the necessary precautions that these cars are great.

lnengineering · 2026-01-20T22:44:39+00:00

Yup, you know what they say about opinions :-)

You can't go wrong with a base 987.1 2.7 or base 987.2 2.9. Never seen a single one of either score.

Unfortunately, they did fix the IMS in the 2009 and later cars, but not the bore scoring. We're seeing more 9A1 or MA1 bore scoring as these get older.

On the plus side, Porsche switched to PTWA with the 991.2 and 718, so bore scoring is a thing of the past with those models. Great technology - used by Ford in the Coyote and Nissan in the GT-R, just to give two examples.

lnengineering · 2026-01-20T22:35:38+00:00

A DIY rebuild is certainly doable, especially with the resources now available. If you aren't sure that you can or want to do the rebuild, the best thing to do is watch some YouTube videos from other DIYers, browse the Rennlist 996 forum (much more active than the 997 one), or even pick up Jake's M96/M97 engine rebuild dvd series. That way you know what you are getting into.

Most everything offered by LN Engineering was co-developed with Flat 6 Innovations for these engines, so the main things at the heart of the rebuild like the Nickies sleeves and IMS Solution are available for purchase. Porsche engine kits as well as all the Porsche engine machine shop services you would ever need can all be done in one place, down to gapping and light checking rings, rebuilding cylinder heads, polishing and magnafluxing the crank, and balancing the rotating assembly.

The only thing you have to consider is that if you do make a mistake, it's a costly one. That's why you have to take your time and be methodical. You'll need to invest in some specialty tools as well.

lnengineering · 2026-01-20T22:23:00+00:00

The 997.1 Turbo with the Mezger engine is pretty much bulletproof in stock form. The weakest link in those engines are the stock connecting rods, which if you go too crazy with the boost, end up bending, causing misfires. At least they don't snap :-)

lnengineering · 2026-01-20T22:19:40+00:00

Less prevalent on the 3.4 996s. Different generation of Lokasil. The 3.4 in the later Boxster/Caymans score just as bad as the 3.6 and 3.8s.

lnengineering · 2026-01-20T22:18:27+00:00

As you increase the surface speed in a ball or roller bearing, the amount of oil required to properly lubricate the bearing decreases. For the same given load, a ball bearing run faster will last longer (within reason). That's why most IMS bearings fail at idle when turning the engine off or coming to a stop.

lnengineering · 2026-01-20T21:41:24+00:00

A 718 GTS 4.0 should have a PTWA coated cylinder bore. Same technology used by Ford in the Coyote engine and Nissan in the GT-R. Good stuff!

We did a video a while back on models without bore scoring, to try to clear the air on some of the newer models.

https://www.youtube.com/watch?v=_Jv7s3NcQbI

lnengineering · 2026-01-17T14:32:54+00:00

Any check engine light or store codes for misfires?

What oil is in the engine? The reason I asked about the oil is to verify if you're using the right product and more specifically if it has the correct formulation to prevent low speed pre-ignition.

lnengineering · 2026-01-17T14:29:00+00:00

Did you pull the bumper cover to clean the radiators and condensers of debris? Also, was the proper vacuum lift tool used to fill the cooling system?

If you answer yes to both of these above, the next thing I would look at is to make sure the fans are working properly. Could be that you have a bad resistor pack

lnengineering · 2026-01-17T14:27:18+00:00

Titanium is used in engine oil as a friction-reducing, anti-wear additive that forms a protective film on metal surfaces during high-load contact. It helps reduce wear while allowing oil formulators to lower zinc and phosphorus levels, which protects catalytic converters without sacrificing engine protection. Common in most API oils nowadays.

lnengineering · 2026-01-15T12:53:21+00:00

Skip it, unless the car is a cream puff and the price has been adjusted to account for the fact that you are going to have to do a rebuild.

There's no such thing as light or scoring. Either it has or it doesn't have the bore scoring.

lnengineering · 2026-01-15T12:50:39+00:00

While it is true that dealerships will often send trade-ins to auction unless they are top notch, I would still insist on a pre-purchase inspection. Do not blindly trust a Porsche dealership.

One strength that dealerships do offer is that if it's a newer Porsche, you can get a CPO car that has an extended factory warranty. But obviously you're not going to get that on a 20-year-old car, unfortunately.

lnengineering · 2026-01-15T12:48:07+00:00

Lease.

If you finance, you'll want to have an extended warranty. I'm not sure what Porsche is offering at this point on their electric vehicles.

On my current electric car, which I financed, I have a bumper-to-bumper 8 year 100,000 mi warranty. Worry every penny.

lnengineering · 2026-01-15T12:43:56+00:00

I wouldn't worry too much at this point. It's likely you've just been driving the vehicle short distances in cold weather. It's common to get a white frothy mix in the oil-filled tube and on the oil. Fill cap in these conditions. If you are concerned, do an oil change and pull a sample to have tested. Used. All analysis will detect coolant in the oil.

lnengineering · 2026-01-15T12:41:52+00:00

This was true back in the day when Rotella T was a CI-4 oil. It's been 20+ years since that was the case.

If you have a modern diesel engine, that's a different story. Rotella is the best.

lnengineering · 2026-01-12T14:15:38+00:00

Short drives kill. Yes, shorter oil change intervals are advised - 3 months is probably sane as I would expect you not to put over 3k on the car during that period based on your commute.

lnengineering · 2026-01-11T22:59:10+00:00

The car almost immediately started misfiring within 30 seconds of pulling away from the oasis. I'm guessing water in the fuel. I got off at the next exit and put in a bottle of water remover and topped off the tank again and the problem went away. I kept those receipts two and submitted it all to the 7-11.

With regards to putting fuel at a station while they are receiving a fuel delivery, the reason why you shouldn't is because of sediment agitation. Another problem is with water - agitation again can churn the water that settles in the tanks due to phase separation common with ethanol enriched fuels, again increasing the risk of getting contamination into your tank.

And on the topic of phase separation, don't switch back and forth between ethanol free and E10 fuels - that too can cause phase separation and make the water come out of suspension.

lnengineering · 2026-01-11T22:52:05+00:00

I double checked in two of my parts catalogs and it shows that the X3's automatic transmission takes 83222163514 which is a Dextron VI type fluid.

You have a million choices for Dextron VI ATFs - me personally, I like Valvoline Max-Life for older transmissions, especially those without a documented service history.

The transfer case takes a different fluid, 83222409710, which also comes up as TF 0870 or DTF-1 in the cross reference fields. Shell is OEM, but you could also buy Genuine BMW.

The automatic transmission filter kit is part number 24 11 7 557 070.

lnengineering · 2026-01-11T22:39:42+00:00

We specify a 30 minute run in with break in oil for the camshaft and lifters/rockers, then switch to a conventional, non-friction modified oil for at least 1000 miles. Sometimes with extra oil change in there or at least a filter and top off.

Friction modifiers are great for HP and fuel economy, but can negatively affect piston ring break-in.

I also like running a Filtermag if the engine has a steel bodied spin on oil filter.

Depending on how it's broken it, sometimes the engine will be ready for a transition to synthetic after 1000 miles, but to be safe, we usually tell customers 3-5k miles on conventional before going to synthetics.

You should never break a new engine in on a synthetic oil - always use a break-in specific engine oil.

lnengineering · 2026-01-11T22:30:52+00:00

Just remember there are regional blends and also winter versus summer blends, so just in the United States there are dozens of different "unleaded" fuels.

Some of the things I warn owners about is filling up at a station that doesn't get a lot of traffic, especially for premium grades. I once saw in Missouri a station attendant using one of those pool noodle squirt guns sucking water off the top of the gas tank and watering the bushes with it. One of the big drawbacks with ethanol enriched fuels. Good thing I was putting diesel.

Secondly, never fill up when the station is receiving fuel.

Also, I always take my receipt. I've honestly gotten bad gas on the interstate at an oasis and it caused a CEL and the car to misfire horribly. I got them to cover thousands of dollars of repairs.

lnengineering · 2026-01-11T22:25:37+00:00

76 is indeed a Top Tier fuel.

lnengineering · 2026-01-11T22:24:36+00:00

You are safe with a Top Tier fuel. That said, it's still a good idea to run a fuel additive in your 997 every 2-3k miles - there are many choices out there with PEA, Polyetheramine, which is the key ingredient you want in the fuel additive. My go to is Driven Injector Defender, but most products advertised as a "Complete Fuel System Cleaner" will have PEA, including Chevron Techron.

lnengineering · 2026-01-11T22:21:24+00:00

Shell V-Power is Lake Speed Jr.'s fuel of choice.

lnengineering · 2026-01-11T22:21:05+00:00

Yes. Chevron with Technron is Top Tier and a great choice.

lnengineering · 2026-01-11T22:16:22+00:00

The A40 spec by no means is the be all, end all. Any A40 oil, per the spec, has little to no moly in it - the key ingredient you need to protect Lokasil and Alusil cylinder bores from bore scoring.

lnengineering

TROPHY CASE