Diagnostic system and method for an engine

Diagnostic system for an engine (42), comprising: a diagnostic module (104) identifying one of a plurality of cylinders (48) associated with a disturbed mechanism for the variable valve lift; marked by a pressure monitoring module (107) that determines a plurality of first average pressure values ​​and a plurality of second average pressure values ​​a fluid supply, which are provided to a camshaft phaser; wherein the diagnostic module (104) identifies the cylinder (48) which is associated with a disturbed for variable valve mechanism on the basis of the first and second average pressure values; and wherein each of the first and second average pressure values ​​each corresponding to each of the plurality of cylinders (48).