Golf L4-1781cc 1.8L SOHC (RV) (1990)
Knock Sensor: Description and Operation
Knock Sensor Location
The knock control system allows calibration of the ignition timing for normal operating conditions, while eliminating the danger of knock or detonation
due to influences by heat, load, fuel quality or engine deposits.
Knock Sensor Diagram
The knock sensor consists of a housing and piezoelectric crystal between two connector strips mounted on a steel bushing. The sensor is mounted on the
engine block between #1 and #2 cylinders and is subjected to vibrations generated by knock (ping). The vibrations cause a small distortion on the surface
of the piezoelectric crystal, generating a measureable voltage which is read by the control unit. When the control unit recognizes a knock condition it will
then retard the ignition point as necessary to eliminate the knock depending upon the intensity.