The intake valve is stuck open.
Hello. I am assuming that you are referring to the intake valve that is located inside of the engine. If my assumption is correct, the only way to fix this issue is to have the cylinder head replaced or rebuilt. However, it may be cheaper to replace the engine itself. If you are referring to the intake that is attached to the enigne, there are flaps that can get stuck open. This can be repaired by replacing the flaps or the entire intake. This can be done by a certified technician, such as one from YourMechanic.