How to Replace Knock Sensors [Chevrolet Silverado 1999-2006]

A bad knock sensor can cause very serious damage to the engine. Before this happens, consult this article on how to replace the knock sensors in your Silverado.

Knock sensors are essential to the functionality of your Silverado engine. They detect any noise caused by a knock and adjust the ignition timing accordingly.

If the sensor is failing, it will not detect the knock and cannot be properly adjusted, which will result in serious engine damage, leading to costly repairs.

Symptoms of a faulty knock sensor include:

  • Engine check light
  • Loud noises coming from the engine
  • Tremors
  • Vibrations
  • Cold start misfires

Follow our guide below which will show you step-by-step how to replace a knock sensor on Chevy Silverado before any kind of problem occurs in your engine.

How to replace a knock sensor on Chevy Silverado

Step 1 – Access the intake manifold

  • Disconnect the negative terminal from the battery.
  • Remove the intake hose at each end (from the MAF and the other from the throttle body)
  • Now remove the throttle cable and the control cable from the throttle body.
  • On the Silverado from 2003 onwards, the wiring harness has to be disconnected from the transmission as well.
  • Remove the throttle cable holder, unscrew the main harness holder from the intake manifold.
  • Unplug the EVAP solenoid sub-harness, MAP sensor, and detonation sensor.
  • Remove the throttle body and vent hoses from each valve cover.
  • Release fuel pressure through the Schrader valve at the fuel rail crossing and use a rag or small container to collect the gas leak.
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Step 2 – Remove the fuel lines

  • Disconnect the fuel lines from the rails with an appropriate fuel line extraction tool. These fuel rails are located at the rear of the driver’s side of the intake manifold.
  • The 1999 to 2003 Silverados have a supply and return line, unlike the 2004 Silverados and above, which do not have return lines.
  • Use the fuel line extraction tool to remove the EVAP line located between the engine and the firewall.

Step 3 – Remove the injectors and engine wire harness

  • Remove the 8 fuel injectors and connectors.
  • Remove the vacuum line from the brake servo.
  • Pull-on the engine harness and unplug the alternator connector.
  • Remove the idle air control valve.
  • Unplug the throttle position sensor on the throttle body.

Step 4 – Replace the knock sensors

  • Remove all bolts from the manifold in reverse order.
  • Remove the manifold and you will see the detonation sensors under the black plugs connected to a wiring harness.
  • Remove the plugs and unscrew both detonation sensors.
  • Install the new sensors and tighten them to 15 foot-pounds.
  • Apply RTV to the plugs to prevent water leakage.

Step 5: Reinstall removed components

  • Clean all surfaces and clip-on new intake manifold seals.
  • Place the manifold on the engine and tighten the bolts in the correct order for their sequence.
  • Tighten each bolt to 44 in-lb and then to 89 in-lb.
  • Position the throttle body and tighten to 106 in-lbs.
  • Connect all remaining sensors.
  • Connect the fuel lines, supports, EVAP line, and intake hose.
  • Connect the black wire to the negative terminal and start the truck to see if the engine knock is still present.
  • If the knock is gone, congratulations, you’re ready to go.
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Knowing the average cost of replacing a detonation sensor or trying to learn how to replace a knock sensor on Chevy Silverado can ensure that your car will perform well for a long period of time. By paying attention to warning signals, such as the engine warning light coming on, loud sounds, and reduced engine power, you can reduce the cost of replacing the total knot sensor.

I hope this guide has been helpful to you and that you can replace your truck’s crash sensors by yourself in an easy and simple way.

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