Anyone hear this on their vehicles? The weather has been really cold here (regularly in the single digits or negatives) but I've never had an engine make knocking noises like this when shutting it off in these temperatures, or at all, before. This was after a 25-30 minute commute and the heat was blowing warm so the engine definitely got up to normal operating temps. If this is normal, fine, but it's weird and I have a hard time believing it should be.
I've always run my CX-9 on premium gas, maybe a few tanks on regular, but that shouldn't matter since the engine takes either. I otherwise don't rev the crap out of the engine, especially not in this cold weather and I don't push the vehicle if the engine hasn't warmed up.
Any theories on this noise? I otherwise plan to call the dealership if the issue persists.