# 2006 GMC 1500 5.3 spark knock

**URL:** <https://community.cartalk.com/t/2006-gmc-1500-5-3-spark-knock/80916>\
**Category:** Maintenance/Repairs\
**Tags:** gmc\
**Created:** [August 15, 2013, 7:07am UTC](https://community.cartalk.com/t/2006-gmc-1500-5-3-spark-knock/80916 "2013-08-15T07:07:21Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![oldbodyman](https://avatars.discourse-cdn.com/v4/letter/o/bbce88/32.png) [@oldbodyman](https://community.cartalk.com/u/oldbodyman)\
**Post date:** [August 15, 2013, 7:07am UTC](https://community.cartalk.com/t/2006-gmc-1500-5-3-spark-knock/80916/1 "2013-08-15T07:07:21Z")

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Hi guys I have a 2006 GMC 1500 4x4 just under 100,000 miles on a GM crate engine, 266,000 on truck, runs great no loss of power, no drop in MPG. sill get 17-18 around town on 87. If I put 90-91 gas in when pulling a load I get 18 all day long. So were is the problem? I am getting spark knock. I have tried diffrent gas, just put in plugs and wires. Old plugs looked good. No Cel on, No codes. It happens when I am flat roads and going up hills. I did get to go away for 1 tank when I switched gas stations,but now all brands of gas do it. This has been going for 3 mo’s. One more thing it all started after I made a 800 mile round trip puling a trailer ( just under 5000 lbs on trailer 2 axle enclosed). On that trip as always do I used 90-91 gas. Any ideas?

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**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\
**Post date:** [August 15, 2013, 7:13am UTC](https://community.cartalk.com/t/2006-gmc-1500-5-3-spark-knock/80916/2 "2013-08-15T07:13:15Z")

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@oldbodyman

I suggest retrieving fault codes

I’ve replaced quite a few knock sensors on GM V8s just like yours

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<div class="post-metadata">

**Author:** ![oldbodyman](https://avatars.discourse-cdn.com/v4/letter/o/bbce88/32.png) [@oldbodyman](https://community.cartalk.com/u/oldbodyman)\
**Post date:** [August 15, 2013, 7:20am UTC](https://community.cartalk.com/t/2006-gmc-1500-5-3-spark-knock/80916/3 "2013-08-15T07:20:50Z")

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I was thinking it may be the knock sensor too. With no codes I did not want to run out and buy one. I will see if I can pull any fault codes. I took it before to my buddy’s shop and could not get any codes to come up. Thanks

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [August 15, 2013, 7:31am UTC](https://community.cartalk.com/t/2006-gmc-1500-5-3-spark-knock/80916/4 "2013-08-15T07:31:39Z")

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I would suspect an EGR system fault.