An internal combustion engine includes an exhaust valve, a plurality of cams Ca, Cb, and Cc used to drive the exhaust valve, a cam-switching variable valve mechanism that selects a use cam used to drive the exhaust valve out of the plurality of cams Ca, Cb, and Cc, and an electronic control unit that determines whether switching abnormality of the use cam in the variable valve mechanism is present on the basis of a locus M in a predetermined period K which is a period in which the exhaust valve is opened. The locus M is a locus of an in-cylinder pressure changing rate dPc/dθ and is specifically a locus indicating a variation of the in-cylinder pressure changing rate dPc/dθ depending on a crank angle θ.

An internal combustion engine includes an exhaust valve, a plurality of cams Ca, Cb, and Cc used to drive the exhaust valve, a cam-switching variable valve mechanism that selects a use cam used to drive the exhaust valve out of the plurality of cams Ca, Cb, and Cc, and an electronic control unit that determines whether switching abnormality of the use cam in the variable valve mechanism is present on the basis of a locus M in a predetermined period K which is a period in which the exhaust valve is opened. The locus M is a locus of an in-cylinder pressure changing rate dPc/dθ and is specifically a locus indicating a variation of the in-cylinder pressure changing rate dPc/dθ depending on a crank angle θ.

The present disclosure concerns a slotted guide of a valve train of an internal combustion engine. The slotted guide includes two guide tracks, which cross one another in a crossing region, for guiding a switching pin of a cam follower of the valve train. The two guide tracks have an on-track region, a crossing region, and an off-track region. At least one radial projection, structured and arranged to protrude beyond the slotted guide in a radial direction, is provided in or downstream from the off-track region of at least one guide track.

The present disclosure concerns a slotted guide of a valve train of an internal combustion engine. The slotted guide includes two guide tracks, which cross one another in a crossing region, for guiding a switching pin of a cam follower of the valve train. The two guide tracks have an on-track region, a crossing region, and an off-track region. At least one radial projection, structured and arranged to protrude beyond the slotted guide in a radial direction, is provided in or downstream from the off-track region of at least one guide track.

The present disclosure concerns a slotted guide of a valve train of an internal combustion engine. The slotted guide includes two guide tracks, which cross one another in a crossing region, for guiding a switching pin of a cam follower of the valve train. The two guide tracks have an on-track region, a crossing region, and an off-track region. At least one radial projection, structured and arranged to protrude beyond the slotted guide in a radial direction, is provided in or downstream from the off-track region of at least one guide track.

The present disclosure concerns a slotted guide of a valve train of an internal combustion engine. The slotted guide includes two guide tracks, which cross one another in a crossing region, for guiding a switching pin of a cam follower of the valve train. The two guide tracks have an on-track region, a crossing region, and an off-track region. At least one radial projection, structured and arranged to protrude beyond the slotted guide in a radial direction, is provided in or downstream from the off-track region of at least one guide track.