GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 6 of 6
  1. #1

    Lightbulb Engine light problem

    my engine light went on earlier today and went to AutoZone to check out what it was. they read the engine light code reader and said that it was my knock sensor. The lady said that it may have just come unplugged and that it happens all the time. She said that its an easy fix and that if it just came unplugged that to just plug it back in and its located on the bottom of the engine.
    Can anyone tell me where i can find it or post a picture of it so i can check it out?
    2003 Chevy 1500 5.3l VORTEC

  2. #2
    Sr. Apprentice WARLOCK's Avatar
    Join Date
    Nov 2011


    Knock sensoes on a 5.3 are under intake manifold. Manifold must be removed to replace sensors. There are 2 knock sensors in there so you better do em both.

  3. #3


    how hard would that be and how long would it take cause its my only ride to work/school?

    ---------- Post added at 08:17 PM ---------- Previous post was at 08:16 PM ----------

    And what could happen if not replaced? would that be bad?

  4. #4
    Sr. Apprentice WARLOCK's Avatar
    Join Date
    Nov 2011


    It is possible they will shut engine down if they get bad enough. Pretty tricky & time consuming job if you are not sure what to do.

  5. #5


    It is a long shot, But one time I did see the knock sensor harness connector (on top of driverside valve cover, in the back, under the intake cover) get so corroded that it starting throwing codes. I pulled it apart and cleaned it very well with some electrical contact cleaner. It has been good for 3 years now! Like I said, it is a long shot. If you have to change the sensors you will have to pull the intake manifold off. It is not that big of a job, but if you do not know what you are doing and end up with a intake leak you will be pretty pissed. If you are going to try it I suggest that you buy a manual for your truck. I have a haynes (like $12 at autozone). It will help with the required torque specs and procedures to remove the intake manifold.

    1995 Silverado 4x4
    6" BDS Suspension Lift-3" Body Lift-Add A Leaf in rear -Trailmaster SSV Shocks-Duel Steering Stabilizer Kit -AirAid Cold air intake-
    4.56 Gears with Detroit Auburn Locker-Pro-Comp Traction Bars with duel shocks-Aluminum Skid Plate Kit-38.5" x 16.5" Mickey Thompson Baja Claws-Constant Dropping fuel gauge

    2005 Yukon XL Jet Power Programmer, Bilstein Shocks, Bilstein rear springs, Helwig Anti-sway bars, EGR Window Visors, EGR Hood Shield, Denali Headlights, Headlight harness upgrade, GE NightHawk Bulbs, White Night Rear lighting system, Russell Braided SS brake lines, PowerStop Brake pads, PowerStop cross drilled and Slotted Rotors,
    2002 Silverado ext cab 2wd (Sold)
    2003 Yukon XL (Totaled)

  6. #6


    Its not hard to replace the knock sensors. They are under the intake manifold, but its a dry manifold (no coolant runs through it) so you just unbolt it, set it aside and the sensors are right there. Theres two so buy two and theres a short wiring harness you may want to get from the dealer because the connections are usually corroded. After you install the new sensors run a bead of silicone around the rubber caps to build a dam around the sensors so water doesn't get in the new sensors.

    2005 Chevy Silverado Z71 Crew Cab
    6" Skyjacker lift w/Edlebrock dual front remote resoviour shocks, single rear remote. Rancho skid-plate.
    17" x 9" M/T Classic Lock Wheels, 35" BFG A/T or M/T tires
    4.10 PercisionGears w/factory locker, T/A Performance rear-end cover
    Banks CAI intake, ported throttlebody, JBA coated headers, over-sized Magnaflow cats, Magnaflow cat back exhaust, Diablo tuned
    B&M aluminum deep transmission pan
    Warn brush guard w/Warn 9.5 XP winch, PIAA bulbs, Line-X bedliner, AWS Black tool chest, Extang tonneau cover
    Weather Tech floor mats
    Cover-Craft seat covers
    Dash mat cover
    Formula One window tint
    One black Lab in rear seat.

Similar Threads

  1. Service light v.s check engine light
    By redbone in forum Chevy C/K Truck Forum
    Replies: 1
    Last: 07-21-2011, 11:04 AM
  2. 99 Tahoe weird tail light/brake light/hazard light/blinker problem NEED HELP
    By beckya99 in forum Chevy Tahoe Forum (GMC Yukon, Cadillac Escalade)
    Replies: 0
    Last: 07-11-2011, 10:46 AM
  3. Engine Problem
    By CarribbeanCowboy in forum GM Powertrain
    Replies: 5
    Last: 09-11-2010, 07:32 PM
  4. Need Help!!! Service Engine Light Problem!
    By Cody115 in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 9
    Last: 10-12-2009, 09:47 PM
  5. Check Engine light problem - please help
    By ajaxajax2000 in forum Chevy Suburban Forum (GMC Yukon XL)
    Replies: 5
    Last: 08-30-2009, 10:47 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts