Engine is currently out for a few things in preparation for a g42, however the only issues we have come across has been the following. -Crank has a few cracks in it, unsure how long they have been there, the noise was their from day one. -Genuine tensioner seemed as if it was not holding enough tension on the guide and the chain had a slight movement to it. -Two lifters where stuck in and had to be forced out. Other than that the engine looks good so take what you will from that regarding the sound we are hearing, but as puff said most of the sound is from valve train/piston to bore clearance. I’ve thrashed the car and am confident that it’s all good, however if after getting new lifters and a new genuine tensioner and unfortunately a new crank fixes the sound I will definitely let you know if it fixes anything.