A device for detecting knocking in individual cylinders of a multicylinder engines comprises a movable vibration sensor, an ignition pulse detector, a control circuit and a control console. The ignition pulse detector is a clip for the ignition cable of the specified which can detect propagation of the high-voltage ignition signal therethrough without damage the insulation. The signal from the vibration sensor is checked for a threshold amplitude at a frequency indicative of knocking. If the threshold is exceeded and the ignition detector simultaneously detects an ignition pulse for the specified cylinder, the control circuit outputs a signal to operate an indicator on the console. The console also includes a selector for adjusting the knocking amplitude threshold.