Systems and methods for unsticking intake and exhaust valves of an engine are described. In one example, valves that may be adjustably timed relative to an engine crankshaft position may be adjusted to unstick intake and/or exhaust valve that are stuck open or closed. In addition, fuel injection timing and spark timing may be adjusted in an effort to unstick intake and/or exhaust valves.

A method of preventing sticking of a CVVT locking pin includes a condition determining step that determines whether a CVVT operation condition is satisfied, an locking-pin unlocking step that unlocks a locking-pin before the CVVT is operated, and a CVVT operating step that operates the CVVT, and a system for preventing sticking of a CVVT locking pin.