i have a 2007 avalanche 5.3 flex fuel
Asked by Webbfamily Mar 01, 2019 at 05:26 PM about the 2007 Chevrolet Avalanche LT 4WD
Question type: Maintenance & Repair
po301 code up then went out. then the motor started knocking loud. what would
cause this
4 Answers
That is a #1 cylinder misfire. Maybe you need new spark plugs.
Webbfamily answered 5 years ago
i changed it. but the engine started knocking when that po301 code came on then went off
1 people found this helpful.
Did the engine knock before changing the spark plug? If not you may have installed a plug with a reach that was too long causing the piston to hit the sparkplug. Remove the sparkplug and inspect it. Also compare it's reach (the distance from the seat to the end of the threads) with the plug that you replaced.