8KaboveMSL

Even if you get price down to where it covers a rebuild, you’ll need to also consider impact of things like parts shortages, etc on the timing of a rebuild completion. If you have a choice, start with a clean slate. Either that or do the equivalent of paying for the rebuild up front by buying a .2 instead. Frankly if you have the time and patience and can get the car ~$20k (US) below market it may wind up being the best economic outcome.

patrickd_21

Killed the deal, thanks everyone!

G.I.G.

Well it sounds like you're doing all of the right things. I would try not to worry about it. If it makes you feel any better, your bore scope pics look like mine from my PPI when I bought my car 3 years ago. I've put 12k miles on my car since then and my car still runs great with no symptomatic signs of bore scoring. My oil consumption, while not great, has remained consistent. I usually burn roughly .4L (one bar on the digital gauge) every 550-600 miles, so about 1 quart or 1 liter every ~1,300 miles.

My advice would be to continue to drive and enjoy the car, and save up for when/if you need a rebuild. I think you might be surprised with how many more trouble-free miles you can get out of your car by taking care of it properly.

I'm not shilling for Millers Oil, but I've had great results using their CFS 10W-50 NT+ for the last couple of years. You can read my review and UOA's here:

Millers Oil UOA and Review

Charles Navarro

I can second Millers Oils. Great stuff. I'd say every bit on par with Driven's oils.

Ed99

This is a great thread and to be honest I think the numbers of cars that has this problem is a lot higher just talking to a few Porsche shops locally. They told me out of 10 cars they conduct the Bore Scoring scope review on 997.1 about 80% of the cars had identified issues. And they told me rebuilding is really hard right now due to sourcing the parts. So brand new looking at around $40K cost to replace which is a huge cost. I was told that manual are highly likely to have this issue over tiptronic if anyone can add to that. For everyone that is looking to purchase a 997.1 it is good to have the car conduct the bore scoring scope test for usually around $300 and they will show you pictures of it. Its worth the $300 otherwise, it can cost you an arm and leg to fix down the road.

G.I.G.

Were they scoping from the bottom of the cylinder (with the oil drained and sump removed) or from the top? The reason why I ask is because most of these cars will show some kind of streaking or scuffing at the top of the cylinder with any kind of miles on the engine. What's up for debate is how long you can drive a car like that if properly maintained before actual symptomatic scoring were to arise.

Also, I believe that the tip cars were more prone to scoring due to the transmission lugging the engine (high torque at low revs), but that might be just anecdotal. Far more 997.1 manuals were produced than tiptronic, so it's hard to quantify.

8KaboveMSL

I don’t know what the replacement cost of engines is these days and I am not sure about the 80%. However, as you mention the parts shortages are real. Given all of this (whether the percentage is 80% or 8%) it certainly makes sense to have bores scoped on any 997.1 purchase.

Coolwnc

Excellent points that you have made! I have a 2005 997.1 with a manual. Went to see if the IMS bearing had been replaced by the previous owner. It was but the install person damaged the IMS shaft but car was running perfect. I decided to have the engine rebuilt. The teardown showed scoring on #6 cylinder. To move forward the engine was rebuilt at 76K miles and cylinder walls had Nickel Silicon treatment done. Car now runs fantastic! Life goes on......

snethss

scoped recently because i saw soot buildup on the left exhaust. No oil consumption whatsoever. No symptoms or sounds.
Perfectly fine ,bottom to top scoped performed.

Is there some other reason the left tailpipe gets sooty?

silver_tt

What year is your engine and how old is your AOS? Have you checked your crankcase vacuum? Doesn't make much sense to have soot in the exhaust if you are burning no oil. When you say it's sooty, is it wet or dry?

jchapura

Overly rich somewhere on that cylinder bank?
Troubled catalytic converter?

Houndstooth

Both of my exhaust tips are sooty and I don’t have bore scoring (at least nothing severe). Car runs perfectly fine. These cars tend to smoke if they aren’t idled for a bit after a hard drive because oil pools in the cylinders. That could cause sooty pipes. Probably just never have been cleaned.

silver_tt

That's more or less what I was getting at. When people talk about a sooty left tailpipe normally that is a red flag for bore scoring. But if the engine was already properly inspected with a borescope through the sump then there is nothing to be concerned with IMHO (at least from the perspective of bore scoring).

If it's not a heavy wet soot and you aren't burning oil that's even more reason not to be concerned.

My tail pipes also get "sooty" and my engine doesn't burn oil. But I say "sooty" in quotes because it's not really soot; it literally wipes right off the tailpipes with a shop towel like chalk dust and it's completely dry. This is nothing to be concerned with.

Fahrer

My 2008C2S had soot on the inside of the tailpipes ( equal on both sides) since break-in. After 38K miles my car use essentially no oil. When the plugs were changed at about 25K miles the tech said they looked great.
This car was properly broken in and always warmed up appropriately (<3K rpm and light throttle until 200F oil temp).

Charles Navarro

Good call on overly rich. It's a good idea to look at the fuel trims and even better to smoke test the engine to make sure you don't have any vacuum leaks if you do find the fuel trims aren't where they should be. Running overly rich for an extended period of time will definitely contribute to bore scoring as you're washing the bores down and going to end up with fuel dilution of the oil.