A system for detecting a fault condition in a valvetrain of an engine is configured to measure one or more operating parameters associated with the engine and determine if the operating parameters satisfy pre-defined corresponding boundary conditions. If so, a pair of values of at least one performance parameter is measured corresponding to measurement on a first and second bank of cylinders present on the engine. The difference between the pair of values is determined and used to compute at least one measure of variation for the at least one performance parameter in a time segment. If the at least one measure of variation for the at least one performance parameter exceeds a pre-defined limit for the engine, the valvetrain is flagged as faulty.