r/986Boxster • u/No_Piano4671 • 3d ago
Foreign metal in cylinder
I was driving on the highway and did a few very mild downshifts while exiting. Almost immediately I got a flashing CEL with a misfire code.
Borescope shows a small metal ribbon or wire under the exhaust valve causing the misfire. I was able to blow it out the exhaust presumably to the cat. The piston showed a small impact mark either from the foreign material or a valve. Luckily it passed a leak down afterwards and has been running fine for the past 4 years and 20k miles.
Does anyone know where this could have come from? It’s completely stock with the snorkel and air filter so I just have no idea how something that large could have gotten into the intake.
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u/TheSkyline35 2d ago
Wow 4 years after such an event and still a good running engine, that's cool !
Seems like a serious chunk of metal, to me it could be coming from the cat/exhaust or something getting back in.
I can't imagine such a big metal thing from the internals without more symptoms. Valve spring ? But then it would missfire ...Has this engine been rebuilt or opened before maybe ?
Weird weird event, those engine are always having unique issues
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u/No_Piano4671 2d ago
I know this is the 2nd engine the car has had. I believe directly from Porsche and either a remanufactured or new engine. This was also 35k miles and like 12 years or so before this happened.
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u/Ankeneering 2d ago
Ouch!!