Ove got an engine knock on a 07 Chrysler 300 with a 2.7?

The 2.7 is a very picky engine. I never had 2.7 trouble but I've heard that they have sludge issue. Even after fixing it the sludge has already done the damage. The 2.7 is a decent engine but once it starts sludging I don't think it will be saved.