シリンダー問題は冷却系の改良で予防出来るという人もいる。FBのコミュより。

Thats why i got the 3.6 motor and directley modified the cooling doe 1500 euro .... because of his advise.

You MUST modify the cooling on 997 (S is a must).... before mod the temperature of my engine went from 80 tot around 110 up and down again to 85 dipending on when the blower went on.
Thats a fluctuation of 25 degree.....

Now its always around 90-95 almost all the time. Such big diffrent....

So the metal in the engine does not expand / and cool down with big temp diffrences when the fan goes on when motor hearts up.

What they did....

Change the Cooling sensor place so it measures the temperaturen behind / after the last (warmest pistons) where the water leaves the engine and not on bank 1 where it enters after been cooled down.

They installed bigger pump that gets 25% more water Through the engine.

they changed the cooling sensor temperature sensitivity so the fan turns on earlier to cool down the water. So the temperaturen of engine does not fluctuate to much ....

Result .... My engine is almost 90% of the time around 90 degrees.