lowpue

What actually causes the bore scoring? How can it be prevented?

msol644

Porschetech3

Not correct, or misinformation/confusion. The Factory short block will have all new parts. There will be less labor involved in installing a short block simply because the whole bottom end will be ready to go, no disassembly/reassembly, no machine work ect. Just have the heads rebuilt and installed and the accessories and thats it..

As far as cost go's , the "rebuild" would depend on the damage/mileage/desired outcome, so even with more labor cost, it could be less than a short block or much much more than a short block.

NuttyProfessor

I've read about many theories on what is the main contributing cause for the phenomena called "Cylinder Bore Scoring". Some argue it can been caused by the pistons expanding faster than the block during warm up in colder climates and with extreme factory tolerances, the pistons begin to rub against the cylinder walls. Others argue it's from "fuel washing" from ethanol gasoline which have poor lubricity chemistry. And, even metal contaminated oils... on and on it goes. Raby uploaded a video showing scored cylinders on a 2002 C4S. He demonstrates how deteriorating iron based piston skirts severely etch into the cylinder walls. Over time, it develops a clear case of scored cylinders. Just search "996 Bore Scoring" in YouTube.

Prelude Guy

I suggest just driving it until it dies. No reason to worry about it and it's probably not worth putting the work and money needed to fix it.

808Bill

I kind of agree here. You can buy another cheap 996 for the same cost of a rebuild...These cars at these prices are disposable...Part out the old one and get some money back!

Prelude Guy

That's why I made the Porsche YouTube videos. Hoping to help educate people on the possible issues when it comes to these cars.

If the car is still running, I would just drive it. Not worth trying to fix one issue when so many others are possible.

NuttyProfessor

OP, what did you end up doing with this car? Engine rebuild? Sell it?

88911coupe

I'm curious how this ended up as well. What is the cost to have the engine re sleeved with L&N? Specifically the process itself assuming the engine was removed and taken apart down to whatever level they'd need to do the work?