Justinj360
Supporting Member
- Joined
- Jan 2, 2014
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The engine knock you hear when the engine is cold and then goes away completely when it warms up is normal for these engines. Something about piston slap and cylinder walls. I read a GM service bulletin about it. I can't find the site I read it on a while ago but this forum does a good job of explaining it. My 2004 Yukon does it, my mom's 99 Silverado does it, and my dad's 2006 Silverado does it. My mom's sounds like a diesel some mornings and then goes away like nothing was ever wrong.
http://www.gm-trucks.com/forums/topic/166511-engine-knock/
http://www.gm-trucks.com/forums/topic/166511-engine-knock/