guariscoc

01 chevy silverado 2500 HD 216k miles. Runs awesome. I can clear the codes and drive around for a few miles then it will throw 2 knock sensor codes. What do you suggest trying first? I was told I could knock on the engine and if it does not slow down then the sensor itself could be bad? Is this true or is it sensing something that is not audible to a very good mechanic.

country_09

if its throwin knock sensor codes then just replace em...it's not hard. me and my bro knocked it out in 3 hrs. with a 30 min break

guariscoc

Yesterday when I started it up I heard something. Ran and got my husband and after it warmed up a little it quit. He says sounds like a lifter to him. I guess those sensors were finding something.

country_09

at cold start these motors have a lot of lifter noise...but if it's throwin the code, get them replaced. the motor isn't runnin at its full potential

guariscoc

Thanks, he tried to explain how they retard something (detonation maybe?) but I am a lost cause. I am a visual learner and there is so much that happens in these things in a split second!

country_09

lol yes. knock retard...if you can, replace them yourself. they're just under the intake manifold sittin on top of the block...the back one is usually the one to go out in these trucks. did with mine bout 4 months ago