Knock Sensor: Service and Repair

1991 Volkswagen Jetta L4-1984cc 2.0L DOHCSECTION Service and Repair

Knock Sensor Location:





WARNING: Disconnect the battery ground strap. Limited space between the alternator electrical connection and the knock sensor mounting bolt may cause an accidental short between the two components.

1. With the ignition "Off", disconnect the knock sensor electrical connectors.
2. Remove the knock sensor mounting bolts and lift out the knock sensors. Take note of the harness routing.
3. Reinstall the knock sensors and CAREFULLY torque the retaining bolts to specification, (engine cold, 15 - 18 ft. lbs.).

NOTE: Verify that the terminals for the knock sensor harness connectors are of the same material. Replacement knock sensors have gold plated terminals. Earlier original equipment sensors have alloy plated terminals. When a knock sensor with gold terminals is installed, be sure to replace the matching harness connector with gold terminals.

4. Reinstall the battery ground strap.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.