Genuine BMW 335i Knock Sensor

BMW 335i Knock Sensor Parts Questions & Answers

• Knock Sensor
  13-62-7-566-786
  Q: What is the purpose of knock sensors in BMW 335i?

  A: A knock sensor is a piezoelectric microphone adjusted to the frequencies of engine knock. Also, if an engine knock is detected, the ignition spark is delayed by the Electronic Control Module. The sensors are secured to the left of the cylinder block.
• Knock Sensor
  13-62-7-566-786
  Q: How to remove and install non-turbo engine knock sensors?

  A: Non-turbo engine knock sensors are under the intake manifold on the left side of the cylinder head. First, disconnect the negative(-) battery cable and cover the battery terminal to prevent the cable from accidentally contacting the terminal. Be sure to read the battery disconnection cautions before proceeding. With the engine fully cooled, remove the intake manifold. Next, disconnect the knock sensor electrical harness connector. Remove the knock sensor mounting bolts on the side of the cylinder block and then remove the sensors. It's important to note the installed angle of the knock sensor on the block before removing it. Reinstall the sensor in the same position and use a torque wrench when tightening the sensor mounting bolt. Clean the knock sensor contact surface on the engine block and sensor before installing the knock sensor. Be careful not to overtighten the knock sensors. Installation is the reverse of removal. Remember to replace the knock sensor mounting bolt, ensure the sensor harness is routed as before, and check and clear fault codes from the ECM memory.
• Knock Sensor
  13-62-7-566-786
  Q: How to remove and reinstall a turbo engine knock sensor?

  A: Turbo engine knock sensors are under the intake manifold on the left side of the cylinder head. Disconnect negative(-) battery cable and cover battery terminal to keep cable from accidentally contacting terminal. With engine fully cooled, remove intake manifold. Disconnect electrical connectors, remove and seal fuel line connections. Be prepared to catch dripping fuel. When working with high pressure fuel lines observe clean working habits. Any dirt or debris introduced into system will cause malfunctions. Disconnect knock sensor electrical connector on left side of engine block. Remove knock sensor mounting bolts on side of cylinder block. Remove sensors. Note the installed angle of the knock sensor on the block before removing it. Reinstall the sensor in the same position. Be sure to use a torque wrench when tightening the sensor mounting bolt. Clean knock sensor contact surface on engine block and sensor before installing knock sensor. Do not overtighten knock sensors. Installation is reverse of removal. Remember to replace knock sensor mounting bolt, be sure sensor harness is rerouted as before, check for fuel system leaks, and clear fault codes from ECM memory.