Replacing knock sensors (BMW X5 E53)

Attention! Avoid interchanging the places of the plug connectors (PC) of the knock sensors. This will lead to engine failure. Mark them with color or numbers.

Replacing the right knock sensors

The replacement of the right knock sensors (cylinders 1–4) must be carried out in the following order. Read the information about faults from the memory of the storage device (SD) of the ECU-KSUD of the "DME" system, turn off the ignition and remove the intake manifold.

Remove the bolts (arrows, Fig. 4.131) and remove the knock sensors for cylinder groups 1–4.



When installing the sensors, clean the contact surface under the knock sensors on the cylinder block. Install the knock sensors and tighten the mounting bolts to a torque of 20 N·m (2.0 kgf·m).

After replacing the knock sensor, it is necessary to read the fault information from the memory of the ECU-KSUD of the "DME" system. Eliminate the faults and erase the information from the memory of the ECU.

Replacing the left knock sensors

The replacement of the left knock sensors (cylinders 5–8) must be carried out in a similar order, only in this case it is necessary to remove the coolant manifold and the pipeline from the coolant pump. Unscrew the bolts (arrows, Fig. 4.132) and remove the knock sensors for cylinder group 5–8.