Fuel injectors.

[Gowing]

Not vintage motorcycle related, but very important for all injected computer controlled combustion engines.
Out beautiful cayenne had piston scoring (sob). I may have contributed to problem by not using injector cleaner enough. When injectors get clogged, the spray washes the cylinder walls. Rings and pistons fail, cylinders get scored.
https://www.callasrennsport.com/blog/po ... re-scoring

[gltriker]

Okay Dave this Topic caught my attention . I've been watching Jake Raby talk about Porsche engines For the past 3 or 4 hours on YouTube !
Are you going to send your vehicle to his shop in Georgia?

I wonder how many HUNDREDS of times he said the words, Bore Scoring.

[Gowing]

We sold wife’s cayenne years ago. Porsche refused to help any of the hundred of cayenne and 911 owners with recall. Many think the scoring is caused by batches of bad pistons Porsche used. There was said to be a problem with the Nikasil piston coating. Rebuilders were finding chunks in combustion chambers. But a clogged injector washing the cylinders makes sense. The Porsche scoring is almost like an oil thread at this point. I should say that it only affected 2003-2004 model years I think.

[Don R]

I've noticed more injector trouble when burning grocery store gas station gas. Name brand with additives is worth the extra cost. My 8.1L gmc dually is particularly prone to check engine lights with plugged injectors. It's hard to drive on by the cheap gas when the wife got 50 cents or more a gallon off at checkout. Saves enough to pay for the Lucas injector cleaner.
Probably time for a dose in her Accord, I notice the gas mileage is falling off a bit.