Hi Everyone.
I'm currently looking for my 997 C2S/C4S, and I'm aware of all the chatter about bore scoring and scoping etc. but there seems to be TONS of speculation about 'What if' etc etc. Wear and tear happens on all mechanical devices, and 997's are no different.

What I'd like some more clarity on, is how many people know of, or have actually had this so called catastrophic failure from bore scoring? Does it suddenly let go? What happens if it all suddenly let's go? Is it a sudden bang, crunch clunk and you're stranded in the middle of nowhere?? Or is bore scoring more of a gradual increase in oil usage, smoking, fuel consumption etc until the decision has to be made to get it refurbished?

I guess all these questions are to get some clarity as to whether when buying my 997, I should also invest in a zombie apocalypse kit to carry in the car at all times in case I'm unexpectedly stranded in the middle of nowhere. Or if things are generally more gradual and I can see the zombies coming from far away and prep accordingly?

Some clarity would be much appreciated. Thanks in advance

 

When your time is up, your time is up.

I guess it's my time. - Rennlist - Porsche Discussion Forums

 

I had something happen once. I was idling in a parking lot, looking at something on my phone. The car (2005 c2) died, and wouldn't restart without giving it some throttle. When it fired back up, I could hear what sounded like a belt hitting the top of the engine lid. I popped the lid and it was immediately apparent that it was not a belt, but something banging inside of the engine. I shut it off asap, and watched all the oil drain out the bottom onto the parking lot... what a mess... (came from between the transmission and engine). Had it towed home, cut the oil filter open to find a glitter bomb. Sold the car as a roller, and started hunting for another 911 a year or 2 later after going through a bunch of other cars that didn't "do it" for me... Wound up back in a 2006 997.1 after really trying to pull the trigger on a 991. Before it "let go" I had changed the oil recently (maybe 500-1000 miles prior, zero signs or specks of metal in the filter (I always checked them), no oil consumption, and I had plans to address the IMS that following winter.


I feel that the due diligence process on these cars should include a bore scope, and thorough ppi. If a 997.1 checks out well, the price delta of 20k or so for a similar 997.2, makes the .1 a bargain, provided you have a rainy day fund of around 20-25k

In retrospect, I'd have just rebuilt the 1st motor in the 1st car to a 4.0, or done a used engine swap...but life wouldn't have allowed for me to address it for a year or so, and the cars weren't priced the way they are now (2018)

 

I had D-Chunk in my 996. Soured me on the marque for a long time.

 

The 997.1 scoring starts and then progresses over time and is caused by the piston rocking in the bore, the skirt touching the wall, removing the anti wear coating on the piston skirt and then metal to metal contact starts and gets.orogressively worse. The 997.2 scoring starts from a cold seizure where the piston gets momentarily stuck at bottom of the bore. This does more extensive damage faster than the rocking scoring in the 997.1 so once a 997.2 is scored it can't be driven as long before it no longer runs.

 

I had bore scoring in my .1c4

 

Not yet. But to be perfectly honest, I do see Cialis or Viagra coming around the corner soon.

 

Not a good response to your question. Others have better ones based on their experiences. So I apologize if this falls in the category of thread hijack. Please see it as an addition instead. Catastrophic failure always referred to engine failure for various reasons. With the PDK introduction, there's another kind of catastrophic failure that will cost about the same as an engine failure. Well documented, I've had two PDK failures, the last one on my 2011 GTS. Final tab: $20,000. Close enough to the cost of a catastrophic engine failure.

 

Most won't have catastrophic failure like the less common IMS problem.... the result of bore score plays out often over years and tens of thousands of miles. There's enough anecdotes in here to suggest that fairly low level symptoms can persist for a very very long time. This is both good and bad, as you will usually have a lot of time to plan ahead if informed properly, but, on the other hand, as it's harder to detect, the less educated owner could easily buy into a problem car. After having a car go through with an expensive engine rebuild, at a minimum I would suggest for potential buyers have a borescope done + be confident the car has been well looked after if it's a 997.1. If not, get a gen2 or one with a history of an engine rebuild with a good aftermarket solution. I hope I didn't put any one off by saying that, but you can definitely get a 997.1 as an absolute bargain over a 997.2, but buy on condition/history and not worry so much about spec/mileage (my mistake).

 

You know I have my car at an Indy now to get new plugs/coils/motor mounts and I saw two other 911s (one a 997.2 and another a 991.1) there that had PDK issues. One of them was flat bedded there overnight. I didn’t think this was really a problem (not that it matters cause I have a manual .1), but surprised to see it really happens to these cars. Guess an aftermarket warranty is needed on these.

 

Thanks for that honest input. Much appreciated and noted, as I'm currently hunting for a .1

 

Wasn't aware PDK was a potential issue. Thanks for this.

 

I now own a 2009 4S that had both bore scoring and PDK failure under the previous owner. I've enjoyed 16k miles on a new engine and new/used PDK since acquiring the car. In can happen to anyone, I don't know the statistics, but the costs are significant if your car's number comes up.

 

My comments are specific to .1 generation.

There are early .1’s that can have an IMS failure. Those can be catastrophic but the good news is that those are imminently addressable. You can tell if a car is in that category by researching the engine #. If it is a car that can have that type of failure, a ~$5k-ish IMS solution solves the problem. This a failure mode left over from the previous generation and it gets a lot of attention but IMHO it’s a bit of a red herring as it can be addressed in the early cars and is extremely unlikely in the later cars.

Bore scoring on the other hand is potentially a real serious issue. Expensive to fix. So doing a bore scope prior to purchase is a must. Doesn’t guarantee that your car will never develop bore scoring but it does give you a level of comfort that you’re not buying a problem.

To your original question, does the problem present itself in a catastrophic fashion?

As Pete lays out above, it typically presents itself over time and unless ignored (or missed because the owner is unaware of what to look for) it typically won’t cause a catastrophic failure. I’ve read stories where owners were unaware of the situation, took car to the track and had it fail there. I don’t believe this is common though.

The one thing you probably need to be OK with when you buy a .1 is installing some mods that prevent/delay the onset of bore scoring, adopt driving patterns the lessen the risk and be willing to be religious about oil change intervals and Used Oil Analysis.

You don’t have to do all those things but a little education can go a long way. Read up and decide what you want to or are willing to do. Regardless of what you decide to do, go into a.1 purchase with eyes wide open and keep in mind these are risks, not things that will certainly happen. Have a strategy for dealing with them if and when they do happen (there are many reasonable ones ranging from buying a warranty to setting aside money for a rebuild). It’s an incredible car and I can’t drive mine enough. I wish I had one of those ant-man things where you could miniaturize the car and take it with you on trips so you could drive it everywhere you travel to.

Best of luck with your search!

 

I must spend way too much time on here as I know exactly the car you are talking about, belonged to Bronz (IIRC) didn't it? That poor guy really got the short straw. There was some speculation regarding abuse the car might have seen before Bronz bought it but nothing conclusive.

As Pete described both the 997.1 and 997.2 can score but the mechanisms are different, unsurprisingly so is the failure rate. I've been tracking them both for a while via the posts on here and data from Charles and Baz, and my completely unofficial opinion is that the scoring in the 997.2 occurs at a rate at least 10 times less frequently than the 997.1. Again, just my opinion but the fact that scoring on Optionman/Bronz's car led to a fifty page thread is an indicator of just how unusual it was.

The thing about 997.2 scoring is it's caused by seizing rather than rocking in the 997.1 (as Pete described). The piston expands faster than the cylinder, which is why it's an absolute must to take it easy and keep the car below 3k RPM until the oil is up to temperature. After that knock yourself out as the piston/cylinder expansion will have reached equilibrium.

As to the 997.1 I sold mine at 91k miles (have a 997.2 now) with no issues so I guess it really is just luck of the draw. I didn't understand bore scoring back then and never took any preventative measures.