2007 Silverado 5.3 V8 with AFM with 180,000 miles

Truck had lifter ticking sound and white smoke upon every start up which would go away after a few minutes, no check engine light

Replacement list :
- headgasket
- valve gaskets
- upgraded drivers side valve cover
- valve stem seals
- intake manifold gasket
- exhaust manifold gasket
- 8 new afm lifters
- 8 new non-afm lifters
- head gasket bolts
- engine coolant temperature sensor
- water pump
- thermostat
- cam sensor
- crank sensor

- spar plugs, spark plug wires, and fuel injectors where replaced 3 months ago

After completion of engine reassembly no longer had white smoke upon start up and no ticking sound but flashing check engine light code p0300.

Code p0300 was for cylinder #1, #4, & #7

Moved coil packs between cylinder #1 and #2 to see if coil packs was bad but no change. Set engine at TDC before installing the rocker arms.

All bolts have been properly torque and no parts have been left unplugged or uninstall.

Any possible advice would be helpful

 

You didn't state if you have a valve job done.?

 

Did not change the valves, took each out cleaned and reseated it with new valve steam seals.

 

Re seated, is that in you lapped them back in? I'd suggest a compression check.

 

You say you replaced the lifters with AFM and non-AFM type - Which lifters are currently installed?

Cyl. 1, 4, & 7 are all cylinders that are shut off during AFM operation - if you’re running non-AFM lifters but still have the solenoids installed and active, that could be triggering the misfires.

 

There are a total of 16 lifters.
There are 8 non amf lifters which were replaced with new non amf lifters.
There are 8 amf lifters that were replaced with new amf lifters.