Quote:
Originally Posted by Dino GT
Yes, but the 9A1 engine is far superior to the M9X engines.
Most of the scoring occurs when the engines are still cold.
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That does seem to be the case. It seems that just because you got the motor scoped and it's all clear doesn't mean the issue can happen a few thousand miles later.
I do read reports of scoring being more common in cars driven in colder climates and obviously in cars driven hard when not warmed up. However, if you go down the bore scoring rabbit hole, there are plenty of cases of well-maintained motors in warm climates suffering from it.
Late model BMW motors like the B58 and related motors have a plasma coatings instead of iron liners. There are instances of these coatings failing in the B58s, the culprit being leaking DFI injectors. I do have to wonder if the DFI 9A1 motors are getting bore scoring from a similar leaky fuel injector issue.
Shame on Porsche for not pushing the easy button and sticking to iron cylinder liners. The fractional gain in mpg of using these cylinder liner coatings seems largely offset by a potential catastrophic failure of the short block at great expense to the owner.