groovzilla

So the Thread should read: "Changed plugs, accidentily may have had broken shot glass shards fall into spark plug holes causing scoring"

Hootsama

This post is chock full o' things that scare the bejeezus out of me: bore scoring, egregious oil consumption, and self-inflicted maintenance SNAFUs. HOWEVER, I am incredibly impressed by and grateful for:

1. The absolutely generous and steady-handed input from @Charles Navarro

and

2. This community that genuinely aims to help 997 owners (somewhat inexperienced, occasionally careless and perpetually paranoid) like me with their four wheeled babies.


I sincerely wish the OP a quick and easy resolution to his current issues with no further headaches down the road. And thanks, again, to Charles and the seasoned vets like @ZuffenZeus for figuring this out.

MexicoBlueTurboS

Groovezilla is a much nicer guy than his photo seems.

yelcab

Just wow! Damn!

silver_tt

In the OP's defense when I first responded to this thread it had a different title. In one of the first few posts the OP was told to change it to "Jake Raby rebuild has Bore Scoring".

That being said it would have been helpful to have all the facts. But my vote would be to not delete this thread. It still contains good information like the deglazing procedure and sometimes I come back to search these threads for reputable information from reliable sources.

This thread is a reminder that it's smart to buy parts only from a reputable source and always using your VIN to be sure you don't get the wrong part. I personally also would have used an OE AOS from a Porsche dealer (many sell online at cost + fixed margin) not using a kit from Pelican. Even OE AOSs have failed out of the box but on a part so important it's still your best bet. Aftermarket AOSs should be avoided. Even if the Pelican one was "OE" I wouldn't be surprised if it's from WorldPac, etc.....

TerrestrialFlyte

Agreed, good info in the thread.

ZuffenZeus

Obviously, you had a failing AOS that was verified by a reputable Porsche shop. I assume either Mack Motorwerks or Velocity Motorwerks. You then carried out the work by yourself instead of paying the shop. (correct me if I'm wrong). Along with replacing the AOS, water pump, and thermostat, you also replaced all 6 spark plugs that turned out to be the wrong parts. As you mentioned in the other thread, they were longer which meant they protruded into the combustion chamber thus coming in contact with the pistons. You confirmed this by stated that the 3 spark plugs on bank#2 all had broken electrodes along the bore scope photographs in this thread. You never pointed that out in this thread which wasted our time.

Your other big concern was oil consumption. All flat 6 engines either from the factory or rebuilt, will consume some oil, but if you have a failing AOS and scored cylinders, oil consumption will increase. The clearances from the FOD gouging allow more oil past the rings. And a failing AOS causes the engine to ingest oil which could eventually lead to hydrolock if not replaced. Countless threads on the subject, especially with tracked M9X based Carreras, Boxsters, and Caymans.

That was another mistake. At this point, it's all speculation based on the facts. What we do know is that the AOS was failing and confirmed by the Porsche shop. You handled the job yourself and botched the spark plug install. As a result, FOD broke off inside the cylinders and you drove the car until the engine exhibited a CEL for misfires. You replaced the plugs with the correct ones, but could have NOT gotten all the FOD out of the cylinders. You continued to drive the car for another 6 months with possible FOD banging around inside the cylinders. As a result, the current shop has confirmed severe gouging as a result as shown in the bore scope images. That's what we know.

Listen to your wife. She seems very smart!

WP0AA29965S716394

As others have mentioned, get the car serviced and checked out in light of the cylinder situation. Provide the PPI and Dyno results and be upfront with the buyer about your mistake if you chose to sell it as-is. IMHO, to repair the cylinder damage means the engine will have to be rebuilt again and that would cost as much as you paid for the car. Not smart given you current property investment situation. I'm sure your wife is thrilled to hear the news.


If you sell it as-is, does it mean the car is not ok to drive and perform in spite of the circumstances? IMHO... no. This car could go years without any problem, but coming on a public forum to gain leverage with a title of "Jake Raby rebuild suffers bore scoring - options and help" without being fully upfront with us about YOUR mistake is just plain wrong. The original thread title and your first post implies that FSI engines are no better than the factory when it comes to cylinder bore scoring. I'm glad I was able to see through this "WRECK" (just for you Tom!) of a thread title. That's a hard pill to swallow and I'm sure some of the tender hearted on this forum will find my comment a little harsh. Like me, or hate me. I don't really care. What I do care about is two men and their companies that have spent the better part of 25+ years provided solutions to these engines.

My best advice is get rid of the car and pour your energy and financial resources into your wife and family.

TerrestrialFlyte

Fair comment, I think.

M3Cavalry

Hoping to learn, as I have a new to me 997.2. What function does the AOS perform (beyond the name), what are symptoms of a failing one, and is it a replacement item based on mileage? Am a little concerned about the oil consumption I am seeing on mine but have only 1500mi to assess. Thanks!

Petza914

As you guys can see, I decided to change the thread title. Not fair to Jake or Charles to have "bore scoring" associated to one of their engine builds when it had nothing to do with the engine they built or quality of their work or processes.

It is a Raby and LN built engine, so I left that reference in the title but removed the mention of scoring. I've also adjusted it one more time so it's clear the incorrect plugs were not installed by FSI as part of the build.

silver_tt

it’s a vacuum oil separator, so it also serves the primary function of regulating the crankcase vacuum. This is why it can be tested easily with a manometer.

you can read more here:
https://lnengineering.com/products/aos.html?mode=list

M3Cavalry

great. Thank you.