Engine troubles after sitting
Hello everyone. I have a 2008 suburban with a 5.3. it has been back in the weeds for a couple years due to transmission failure (only 2000 miles on transmission rebuild, owner died). I didn't have the time to mess with it so I just went and bought a newer one.
Now I'm wanting to fix it to have a backup and when I started it up after being off for a couple years it now has a nasty knock. It sounds like the top of the engine. It sounds like valves are hitting the piston if I were to guess.
What would cause it to just start having troubles after sitting? It ran smooth as can be before.
Could this be afm system? If so, what would be the diagnostic to confirm?
I'll spend the money on the transmission but no way will I spent it on transmission and motor. If this thing didn't have a perfect leather interior and near perfect exterior I wouldn't even bother.