GM techs inside please

Billydroveit

Billydroveit

Club Member
2002 GMC 2500HD 6.0 LQ4 131,000 miles

So i've had an issue that keeps getting wrse with the weather. I have no SES light, and the truck runs great. Here;s the issue. Once it warms up and the temps are above 50 to 60 out everytime i lean in the gas peddle any harder than normal driving it starts to spark knock. It's not really affected by gasoline brand or octane. I have no oher issues with the truck and the SES light doesn't come on. I do have one spark knock sensor that's not responding to a tap test when i test teh sensor. I have a new harness and will be getting the new sensors and replacing soon. Would one knock sensor not working cause this? The other one works fine. Or could i have a vacuum leak. I know these trucks have issues with the intake gaskets??? Just not sure what it affects.??

Thanks in advance.
 
had that happen with my 5.3... except it was from the iridium plugs being bad... i was cheap, it was a lease, and it needed a tune up anyways so thats what i did and it stopped
 
the old trucks had gaskets problems. ls family is a dry intake(no coolant). check fuel pressure aafter you replace the sensors if that doesnt fix it
 
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