ZuffenZeus

Both my mother and sister got breast cancer at the same time. The doctors told both of them to NOT wait because the cancer growth was small and they could beat it with treatment. My sister waited, my mother didn't. My sister died less than two years after diagnosis. My mother took the treatment and beat it. She is still going strong. That was four years ago.

Cylinder bore scoring is like a cancer and if your engine have been confirmed to have the early stages of the problem, then don't wait. You could risk damage to other vital components and even worse.

SammyTheBone

It's possible. But only one way to know exactly where you stand. I rebuilt the engine in my 03 C4S last October. Nickies from LN and had Hoffman Machine do their magic with the heads. Addressed the other weak links "while in their". Went 3.6 --> 4.0. It was expensive, but holy smokes does the car RIP now. Couldn't be happier with the decision to do it and I couldn't put a price tag on the confidence and the feeling of accomplishment that came from having rebuilt the engine myself.

I have no clue of your financial situation but if you scope it and see little to no scoring then there are some things you can do to slow the progression (search to find loads of info on that) buying you a little bit of time to plan and save.

JohnAndrew

Thanks to all the replies. Its weird tho because the car does drive fine with no other symptoms of bore score except the metal that does look like Ferroprint. What I was reading elsewhere is when there is ferrous metal with lines it is severe bore scoring. I just can't believe that. Car also wasn't a true cold weather car. Virginia and Nebraska, now NC.

SammyTheBone

My car drove fine too. I had severe scoring on cyl. 4&6, mild scoring on cyl 5&1. There are PCA videos and Jake Raby/Flat Six Innovations videos on youtube that do a great job explaining bore scoring causes, symptoms and solution.

hbdunn

what vital components have been confirmed to be damaged by bore scoring that wouldn’t be replaced during a rebuild?

wildbilly32

While cold weather is not the ultimate determining cause it does get cold here: Other factors play a part in this failure process.

JohnAndrew

I guess it's time to go 4.0 build. Already got X51 might as well go bigger bore now.

ZuffenZeus

The better way of saying it is... What engine components are reused but could be potentially downed upon inspection during a rebuild?

Answer - the big one is the crankshaft. An extremely costly part and can easily add another $6,000+ to the rebuild process. Another are the camshafts. Remember, when you lose the piston skirt coating, you're getting Al to Al contact. The scoring process is like a cheese grader shedding metal into the oil which turns it into liquid sand paper. These engines have tight tolerances. Metal laden oil will work to permanently damage the journals of the crankshaft, lobes of the camshaft, IMS bearings, etc. Over time, metal could build up and clog oil passageways leading to a catastrophic event (like on the track) where the much needed oil is blocked.

GC996

Sorry to hear John. I would get the bores scoped to see how bad and how much time you have. Plenty if FSI videos on the topic and what to do with oil and procedures to prolong life until you are ready to rebuild. Sounds to me like you have a keeper regardless. We all will be facing a rebuild someday. Looking forward to learning about your journey.

GFern

I found a similar piece when I cut my oil filter this last change. When I did plugs a couple of months ago I had a look in the bores and they all looked totally normal. I am switching from Driven DT40 to DT50 oil. Car only has 62k miles, I'm the second owner and has been owned in AZ and TX it's whole life so it has never seen cold weather. It must just be a matter of time and not mileage. If I hadnt cut the filter open, I would never know anything is up. I wonder how many cars out there are driving around with this coating missing from the skirts for years, with happily oblivious owners before ever developing actual bore scoring. I've made peace with the fact that the process has started, and will just rebuild it when the time comes. In the meantime, its only a weekend toy, so I'm just going to keep enjoying the car for twisty road rips and hope I have some time before I need to dump the $30K into a proper build.

JohnAndrew

I'm kind of thinking same thing. Will scope bores when I do plugs here shortly and spoke to my buddy who works on these cars for a living and builds these cars for customers for track use and his whole theory was "hey if you have no oil consumption, noises, etc, just drive it". He also said same thing, how many people are actually ripping apart oil filters. I will rebuild but not right away on a few pieces of metal. Also just put 4 hours and 250 miles on car over weekend and no oil consumption what's so ever.
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