[captjohn22]

Yes mine are 6 cyl.
I think air is more of a problem with common rail engines because of the higher pressures in the fuel system.
My personal boat has cat 3208's. Like most older engines if they get air bound you can crack the fuel fittings where the lines go into the injectors, then crank the engine until fuel runs out of the tubing. Re-tighten them and start the engine.
This should NEVER be done with common rail engines because the pressure in these lines is much higher and can cause serious injury.