Not much to add to dporto's comments. But I agree with you. Drive it and enjoy it.
Do your homework and stay ahead of the oil changes. Especially if the car sits, undriven, for long.

Yes - there is plenty of confusing and conflicting information on these cars. Learning who to trust, and believe, is half the battle.
Welcome and best of luck with your "new" 996.

 

Every car will _eventually_ have some catastrophic failure - but not every car gets you in the feels like the 996 does. Don't save your 996 for the next owner...enjoy it while you've got it, don't overthink it.

 

[QUOTE=dporto;16387663]Keep on reading and weighing the "facts" (there are plenty of real and "alternative" ones floating around). ALL engines will eventually fail in some way - including the M96. It seems like the occurrence of engine failure is elevated here, but that's mostly a function of "the nature of internet forums" - i.e. people come here to commiserate with others who share their passions and problems. These cars (including the engines) are very well made/engineered - this is not to say that they have no problems - they do. After all, it's a "performance car" and along with the positives come some negatives - partially due to how these cars are used (they sit around in the garage sometimes for weeks or months at a time, and then we jump in and "drive them like we stole them"...). The key is to drive it, and maintain it - 5k mile oil changes are a must, using a high quality oil (not even going to open this can of worms - read, read, read), address certain issues at set mileage or time based intervals (water pump, cam chain pads, IMSB, fuel filter, etc.). Get "Tuned in" to the normal noises, feels, smells of the car and don't ignore when something changes or something new shows up - identify and address the cause as well as the symptom before it turns into something substantial.
Good luck [/QUOTE

While those are good points for a new car owner, these cars are 20 years old plus. The manufacturer recommended oil changes at much higher intervals, This specific problem that has been found and there are no remedies that have been proven to work.

Pretty simple really, but the car and hope it doesn’t get worse, when it does address the situation by spending about as much as the car is worth, or move on to a car that doesn’t have these known problems that are associated with it. It’s really a monetary argument as if all of us had the money to spend,I for one wouldn’t be dealing with a 20year old car, but driving a new one.

 

[QUOTE=cdk4219;16387755]Wow... talk about circular logic! It doesn't matter what the manufacturer recommended 20 years ago - it's clear that they were wrong. Nothing I recommended was pertaining to a new car purchase. If I wanted to drive a Lexus, I'd buy a new one. In fact, if I wanted to drive a 991 or 992 I'd buy one of those. The fact is, my 996 is perfect for me. I bought it for cash, pay for all mods with cash and have built it exactly as I want it to be. I couldn't go out tomorrow and buy another one like it. Yes, it's a monetary argument - These cars are WAY more expensive than the $15-$20k price of entry (which is about 1/4 or less the initial selling price when new). If you expect to be in for the long haul, it will cost you many times your initial buy-in price to stay in the game. If you're just testing the waters/thinking about this sort of purchase think hard and long before taking the plunge.

 

Was the scoring seen from the sump with the piston at TDC or from the spark plug with piston at BDC?

 

My question to you is , does it really matter? The guy is contemplating purchasing a car with evidence of the expensive problem. It may be different if he already owned the car and is trying to figure out when it’s going to go south, but he’s not. Would you buy this car knowing the fix is probably as expensive as the car?
If the car you own has developed the problem, either drive it or fix it. If your contemplating purchasing a car with this problem, at the price point these cars are, it would be better advice to move on and find one that doesn’t show signs of this particular known problem.

The real simple answer to the original question is that any bore problem that is found with a plated cylinder design isn’t going to stay the same or get better with time. The only repair that can fix the issue is costly. I really find it hard to believe that anything but this answer could be found on a Porsche forum, especially a 996 thread.

 

It does matter. It is usually bank 2 that scores first, not bank one. If there isn't anything wrong with the bores with the piston at TDC, it was likely a dirt particle or some other fod that scratched the bore and likely isn't bore scoring. Bore scoring typically starts at BDC and makes its way up the bore as the problem progresses.

The Lokasil bores are not plated - they are raw aluminum that is etched to expose the silicon matrix that supports the pistons and rings.

 

So you would suggest that the OP go ahead and purchase the car with the possible issues? Or better yet would you purchase the car with the possible issues?

 

If it was me, yes. That would be negotiated at time of purchase and I would just plan that I would be budgeting for a build at some time in the future. It's a calculated risk, as is purchase of any used vehicle.

 

Charles - you have my cylinder blocks. If you look at post #5 of this thread - that is a photo of cylinder #1. I did not detect any significant scoring in the other cylinders. Maybe I didn't look closely enough. What is shown in that photo: is that not bore scoring?

Regarding scoping bank #1 from the sump - is that even possible? I had a hell of a time even accessing #4 and #5 when I took a look.

 

His reply is very clear and self explanatory.
.

 

I can't comment on anything as your original cylinders are aluminum chips already. From the picture, it looks more like scuffing, however that amount of damage would have been a downer regardless. It's possible coolant in your oil from the cracked #5 was the source of your abnormal cylinder wear.

We usually don't scope bank 1 from BDC as I have never seen a block with scored bores in cylinders 1, 2, or 3 without cylinders 4, 5, and/or 6 being scored.

Not having a picture of what the OP saw for the scratch in cylinder #1, I can't definitively say in his instance it's actually bore scoring or just a scratch from fod from poor air filtration.

 

this was one of my cylinders at 96k miles. The valve seat broke apart but I was idling at a gas station and turned it off within a second. Dunno if the scoring as due to the valve seat but sure doesn't look like it. Regardless, we chose to leave it as is.

Car went another 80k miles (Had 180k at castatrophic failure on track). Car had more than its fair share of 'hot suppers' and track time (at least 5-8 per year, every year since 1100 miles on the odometer when new).

You make the call.

 

How much money would you negotiate for this said car knowing the calculated risk is higher for this particular engine? And how much should he budget for this rebuild?

 

Thanks for sharing. This is why I asked my question. That's not bore scoring and is likely what they saw. That's from FOD (dirt, carbon off the top of the pistons) being ingested.