Steph1

[QUOTE=Charles Navarro;16066031]Thanks for that, I just spent the last 20 minutes trying to find that article that I came upon this morning by accident, and frustratingly can't seem to find it again. But thanks for your input.

FamilyMan928

No Bore Scoring found.
I recently purchased a 2007 997.1 4S with 43k miles (manual trans). I had a PPI done before purchasing the car and also had a bore scope done. Everything checked out good (I saw the pictures and am waiting for the shop to email them to me).

In the 3 weeks of ownership I've put on nearly 600 miles and it's been a pleasure to drive. No leaks, squeaks or rattles. And I make sure to short shift (~3k RPMs) until oil temp reaches 200F (I can only hope/guess that the previous owners did the same?).

Sporty

Charles -Base models (911) have the 3.6 and in your next sentence you say "base models do not score" - assuming you are referring only to base model Boxsters? I guess I am answering my own question. Thanks.

gmiz

So having read this thread, I am not sure if:

1. there is anything to do to prevent bore scoring (low temp thermostat, oil changes?)
2. Lower or higher mileage cars are affected more - the theory that a car regularly driven might be better even in a cold climate?
3. 3.6 vs 3.8 more prone- Ive seen references to both here and other threads

About to potentially send a 07 C4 for a PPI, with 82K miles - winter driven year round car in Canada - I plan to do the same.

Willing to jump in on this if I think I can reasonably reduce the risk - but numbers like 12% affected and climbing have me thinking about a TT instead

Can anyone clarify please?

Charles Navarro

And Cayman. I've never seen a 2.5 or 2.7 engine get scored bores. Same goes for the 3.2 Boxster which also received cast pistons, which again, don't seem to have the piston skirt coating failures that end up with scored bores.

Charles Navarro

There are no absolutes. Short drives are the worst for sure, especially in colder climates. The additives in the oil require temperature and pressure to activate. Short drives also do not let the oil get hot enough to vapor off the moisture which combines with combustion byproducts to create acids. Lastly, fuel enrichment in cold start dumps excess fuel into the oil, which also contaminates the oil. That's why cars need shorter drain intervals, especially when driven short distances and/or cold climates.

For sure, I'd make sure to bore scope the engine with piston as TDC as Jake has advised in his Rennvision series.

Based of the available research, higher ZDDP levels and Moly levels can help extend the life of Alusil and Lokasil bores.

All models with forged pistons are equally susceptible to scoring.

Prairiedawg

Is that possible to do on a 9A1 engine?
I've watched most if not all the videos and it seems most of this applies to the previous generation of engines.

Flat6 Innovations

My current videos do not pertain to the 9a1 engine. The process is different, and much more difficult to approach from inside the oil sump, right now for the general shop, and enthusiast a spark plug accessed inspection is the only choice. With that, you are only seeing 1/2 the picture, but in some advanced cases of scoring, that's enough to prove that scoring exists.

Prairiedawg

Thank you for confirmation. It seems most of what I have followed shows scoring on cylinder 1 almost exclusively in 9A1 engines. I am in the process of locating a PPI provider for a car I'm looking at. I would have them start at #1 and go from there. In your experience, has scoring showed on other cylinders as well in the 9A1 engines? Car has 16k miles. I know the mileage is low but sometimes that doesn't seem to matter.

Flat6 Innovations

We have seen scoring on all cylinders with the 9a1 at some point. The most prominent is #1, but that doesn't mean that any other cylinder should be discounted.
Start on #1, and if you find scoring, there's no need to go further, but if you don't find it on #1, then scope the entire engine. It may still exist, because bottom access to the under side of the cylinders is so difficult to achieve, and requires medical grade tools to perform. There's also the risk of breaking the camera inside the engine.

Prairiedawg

Thank you, sounds like the logical path. I'd probably just have the shop change the plugs since they're out if the cylinders look ok.

Thanks again. Much appreciated.

Flat6 Innovations

Lots can be learned from reading those plugs. Post pics of each one numbered here, and I'll read them for you.

Prairiedawg

Thanks, I'll take you up on that. Could be educational for everyone. It will be a few weeks before I can. Out of town purchase so I'm still trying to find the right provider in Houston. One told me pulling a DME is enough. No check engine light, no problem then. We all know that's not true. Doesn't inspire confidence. Other shops flat out won't do PPI 's. I'll probably post something about this on another thread to keep this on topic.

russm535il

I have not had the problem but think it is inexcusable for Porsche not to fix this under warranty !

gary11

How can you scope the bore with piston at TDC?