I have a 2002 chevy Z71 silverado 5.3L and when i really get in the throttle about 3700 rpm and upit starts making a rattling noise from the engine. kinda sounds like the valves are making noise And the check engine light will come on for about 10 sec. BUT when i dont get in the throttle it sounds normal and no check engine light. i talked to a guy who said it could be a nox sensor???


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The rattle noise is referred to as ping or knock. If your CEL was lit pull the DTC code and see if you have a problem with the knock sensor and / or something else.

 

Check the DTC!!