Quote Originally Posted by nissannewby View Post
Possible faulty injector. Not atomising correctly meaning one cylinder running richer so hotter. No effects on engine temp as its only 1 cylinder. Extra heat from the faulty injector can cause the cracking and melting.

Only my theory though.
X2 on this one I know there is a lot of talk about piston cooling squirts causing piston melt down but I think injector driple is more to blame but gets overlooked as the piston melts and destroys the evidence
Cheers Kimbo