Silverado Knock Sensors!

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by chevysr2004, Aug 6, 2007.

  1. chevysr2004

    chevysr2004 New Member

    I own a 2000 Silverado Z71 3dr ext cab 5.3L and my SES light came on. i checked and i am getting back code PO327 and PO332 (knock sensor circuit, low output). what is the easiest way to determine if the actual knock sensors need to be replaced or if its the knock sensor harness connector?
  2. Cableguy

    Cableguy Epic Member 5+ Years ROTM Winner 1000 Posts

  3. chevysr2004

    chevysr2004 New Member

    Thank you for the help. Anyone know how hard it is to get to the knock sensors and what tools are required. I'm pretty sure they are under the intake manifold, which doesn't sound like fun.
  4. Cableguy

    Cableguy Epic Member 5+ Years ROTM Winner 1000 Posts

    They are under there, but can't help you with tools. Sorry, Never done one on a 5.3L
  5. Oldbear

    Oldbear New Member

    There is a bullentin on that from GM (where I work) "0332" is a ground fault in the knock sensor wiring set off by moisture (there are two, but it won't tell you which one). Easy to get at - just remove the intake manifold, the sensors sit in a metal valley pan. Don't remove the pan, just the boots over the sensors and the sensors themselves. Put in new sensors, silicone between sensor and boot and wire and boot. Replace intake manifold, with new gaskets - your in there anyways... And your code should stay cleared.
  6. Oldbear

    Oldbear New Member

    And yes, you will need a tool to disconnect the fuel supply line from the fuel rail. But, other than that - nothing but an average tool kit. Ask your local GM/Chevy dealer for a few pictures of the intake manifold and knock sensor locations. Any nice parts guy will do it for you, maybe with a coffee or dounut... we parts guys work for these all the time
  7. unplugged

    unplugged Epic Member 5+ Years 1000 Posts

    Some info that might help:
    From: Allexperts
  8. sportnot

    sportnot New Member

    Hi, let me just add, I just replaced my knock sensor#2 two months ago, with silicone, and got an alarm again. It, and #1 had 100k-ohms, and 0.2V AC when knocked with hammer on block's side (suppose to be 5V, but digital meters never show spikes). I took off the upper manifold again, and found the #2 sensor was rusted again. I asume water is running down the wire, so $50 later (because I did not want to trust a rusted sensor even though it checked out) I replaced it and siliconed everything. A few things I learned: don't use anti-seize (the voltage is weak already), tighten to 10-15ft/lb, and double check that the well is clean of all rust and water (it is hard to see, unless you jump on your engine). Good Luck.

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