I know that this thread is for data purposes and the mods can feel free to delete this post but I thought I would throw something up for you all to think about.

I am not a mechanical engineer or engineer of any sort, so don't shoot me down, but this is just a thought;

A conventional gasoline engine usually has say a alloy head and cast iron exhaust manifold that is sometimes connected flush to the heat without a gasket, sometimes with a gasket in between, no doubt these two have different properties in the way they are made up and in there molecule structure and have different heating/cooling characteristics....

I was informed that the head and the exhaust manifold are actually one piece on these motors now, despite being a carry over from the previous model.

The point I am trying to get to is, could it be possible that as it is ALL the same piece of alloy, could some of the heat that is meant to exit through the exhaust system be transferred back into the area of the head around the cylinder chamber and be causing the pre-ignition? I remember years ago coming across a crysler/mitsubishi motor that would develop a hot spot in the head and this would cause pre-ignition and even running on to an extend.

Again, I could be completely off track here, but these engines have that many sensors that if it had been a computer/software problem surely it would be able to rectify it....