C4SDream

FYI this is not my video, I have zero affiliation with this person/video. Thought it would be something to share, don't come at me. Only posting because I have spent wayyyy to long reading about 997.2 boring scoring and have only seen a handful of people posting proof.

Just got my .2 and did my first oil change today and before doing the oil change, wanted to watch a video to make sure I was doing everything right/had everything I needed. Well I came across this guys channel and saw this video.

I know the 997.2 has had a very small amount of bore scoring cases and I specially went with a .2 due to the .1 issues but this is a little alarming. Under 30k miles and already seeing some marks.

The scoring doesn't look bad at all in my opinion FWIW but this is my first P car so don't listen to me.


Again, only posting for people looking at .2's and cant find decent proof the scoring is out there.

Wayne Smith

I'm not sure, given the reflections, exactly what I saw there.

In my searches, I've found the 9A1 motor crowd seems to isolate cylinder wear into three categories ...

1. Cold seizure. This generally occurs when a car has been driven hard when cold and appears towards the bottom of the cylinder. The closed deck design is credited for this failure, and it can be serious. The user is responsible for avoiding this.

2. Bore scoring. This is a lot like cold seizure in appearance, and quite frankly, there is debate about which is which. But in general, from the gurus, the 9A1 general failure is seizure as opposed to scoring. The good news here is that this can be avoided with proper use.

3. Cylinder streaking. There seems to be a general consensus that a bit of streaking is normal and that this causes no short or long-term adverse effects. If anything, that is what I think this video shows. But some of the marks seemed to be going around the cylinder rather than along it. Again, I'm not entirely sure what I was seeing.

My thought on the streaking is that with DFI motors, we do get some carbon buildup. If a piece of carbon breaks off, entering the cylinder, we could see a streak from this. Shallow. Not penetrating the coating, causing no actual harm. This is a good reason for Techron (just IMHO, no affiliation) and the occasional PEA concentrated injector cleaner. This won't address the back of the intake valve, but it will keep the pistons clean, hopefully.

Beyond the above ... I picked up a borescope camera a month ago, thinking I'd be coming up on my spark plug change time. I promised to post my results. But I was wrong about that. My long Covid still has me searching for words and using paper for mathematical computations. It wasn't until I went to my 997 maintenance chart that I realized my memory was also compromised. It appears that just after I "recovered" I opted to fill a couple of days proactively doing maintenance. I've got some time before I'll be doing my plugs.

In the meantime, let's keep the 9A1 videos coming. Thanks for posting this.

PS ... When buying a borescope camera make sure it has 2 or 3 camera lenses so you can get that 90 degree view.

Petza914

No scoring in that video and very light scuffing - not much to be concerned about IMO. It's so light, it almost looks like what happens when running either aftermarket air filters that haven't been maintained often enough or a dirty OEM filter.

C4SDream

After market filters can do this? My car came with K&N's, I've run them on every car I ever had. I wash/clean at least 3 times a year which is overkill but I like to make sure the car is clean. I just washed and reoiled but if they can cause this I might need to switch to OEM.

Ed99

Are we starting to see more 997.2 cars with bore scoring now?

silver_tt

Not really. The 997.2 can score but it is far less common than the 997.1. Will we see more over a much longer period of time? Ya probably but overall I think it will be far less % than the previous generation. I believe folks like Charles Navarro have said the 9A1 scoring is currently a small % of what he sees come in the door.

Busta Rib

Monitor the Bore Scoring thread that is sticky-ed in this forum (https://rennlist.com/forums/997-foru...r-997-2-a.html). Over 14% of .1 and 1.7% of .2 owners reported bore scoring in the poll. It's not definitive but a good data point that shows that so far scoring is not as prevalent in .2 cars.

cvalue13

would be nice if we had a way to see those percentages over time.

because some argue that the delta in % is in some part a function of the delta in age/milage

on that view, the better data wouldn’t be eg as of today 14% vs 1.7%, it would look more like, eg:

• today, a ’09MY .2 @ 15yrs old is X%, vs

• back in 2018, when ‘04 MY .1s were also 15 years old, were Y%


so on and so forth

i personally own a .2 and so am biased in hoping such data would continue to show a significant delta in %s

but this counter-view I restate above leaves open the question of whether the delta in % is at all an artifact of .1’s being on average 6yrs older/miled than their counterpart .2s

festina-lente

I'm dumbfounded that after 15 years we can't conclude that the 9A1 engine is all-around more reliable than the M96/M97.

groovzilla

Over the past 6 months I've seen on other Porsche Forums & for- sale listings a lot more 997.2 engines with Bore Scoring.
Have also seen several 997.2 cars for sale as rollers. Craigslist, Facebook Marketplace, etc

Petza914

997.2 is definitely more reliable, but it's not bulletproof, as was originally thought that it might be. Still worth a premium over a 997.1 by about half the price of an engine rebuild, so roughly $10-12k over the exact same car in a 997.1.

festina-lente

Perhaps we need to start a new thread specific to 9A1 failures around the web.

festina-lente

Nothing mechanical is.

silver_tt

For all intents and purposes "bulletproof" is a term in this space that describes the robustness of the engine design. A design that scores more often would be less bulletproof. For example the Mezger is widely regarded as bulletproof but I know I could break one if I really tried....... we definitely know the 9A1 is more reliable than M9x, that is not really up for reasonable debate. But you can still down a 9A1, no one is saying you can't.......

Hula

I switched from K&N back to OEM. Over oiled or too dry can cause issues but well maintained K&Ns are fine. I went back because it's a maintenance item with no real benefit. When they designed the 9A1 they designed it with future development in mind so the stock airbox is somewhat oversized. It breathes well already.