GEN 2 BORE SCORING
Well done 911&PW for consistently getting down and dirty with the hard facts and truths behind modern Porsche ownership and engineering. I refer to Chris Horton's ongoing investigation into bore scoring with 997 gen 2 engines, and notably the case study of a 2010 997 Turbo DFI engine, it certainly makes for interesting reading even if there isn't a definitive answer or pattern and, as Chris says, everyone loves a 'whodunnit.'
Placing the blame with the injectors does sound plausible, particularly in view of the harsh working environment of a DFI engine. I have a vested interest because I have a DFI 991 of 2012 vintage, which has so far been faultless, but even so I will be getting the injectors’ resistance checked out, after the graphic image of the six injectors from the affected engine. After all it can't do any harm and it may offer a useful early warning. Obviously physically checking the injectors on a DFI engine is pretty much impossible, without entirely removing the engine. Oh, for good old Bosch injectors on an external fuel rail, that can be removed by a simple twist and a tug!
Like many, my Porsche is a second car, so doesn't always get the long journey that it deserves. One thing I always do, though, is deactivate the stop/start. I don't care what anyone says, but this sop to emissions can't do an engine any good. Constantly squirting a start-up quantity of fuel into the bore must promote some sort of bore wash. Modern solutions and unintended consequences spring to mind. James Prior, via email
Steve Bennett replies: We pride ourselves here at 911&PW in getting to the bottom of all manner of technical issues. Rest assured we will continue to monitor the bore scoring issue and maybe one day arrive at a definitive answer.