When they run it on low power mode (lean fuelling/retarded ignition etc) it sets up vibrations in the engine that rattle it to bits eventually
No, I think the vibration problem occurs when they try to run it at full power, so I guess it’s setting up harmonics at high revs that are damaging other components. Apparently, they did a lot of test bench work last year using single cylinder prototypes to develop the internal combustion engine. They thought that was successful and the complete engine was a major improvement when tested on the dyno. However, once they installed it in the car, things kept breaking whenever they tried to run it at full power. Alonso’s P7 suggests that they have sorted out some of the problems and managed to turn up the power a bit, and also that the car itself is reasonably competitive. If they have managed to sort out the vibration issues, then they should be able to focus on power and efficiency. They seem to have the fourth fastest car now, so it’s not impossible that they are faster than Red Bull by the end of the year. If that’s the case, Alonso might decide he’s better to stay put than gamble on Renault or Ferrari. Unlikely, for sure, but not impossible given that P7.