Well after a good run, it seems the truck is fighting a Cylinder 7 misfire that came up today. I think my son hasn't been diligent enough with monitoring oil levels based on the fact it was 1.5 quarts high and there is a p0521to be
2011 CHEVROLET Silverado 5.3L V8 3GCPKSE3XBG305530
Odometer: 257,790 mile
P0307 Cylinder 7 Misfire Detected
P0420 Catalyst System Efficiency Below Threshold Bank 1
P0521 Engine Oil Pressure Sensor/Switch 'A' Range/Performance
I'm noticing a sporadic tapping metallic noise at idle, where do I go from here? Thinking of pulling the valve cover an taking a look. I'm guessing broken push rod, lifter, or rocker arm.
What is worst case scenario?
What is best case scenario?
Best case, broken valve spring that hasn't interfered with valve and piston yet. Worst case, lifter roller is fubar and wiped the cam lobe. Get the valve cover off and check operation of cylinder 7 vs others. Then go from there.