6.5L Puffing Black smoke when accelerating
 

Also very hard to start when cold. My guess is glow plugs injectors and air filter. Any thoughts?

Thanks in advance.

air filter ,exhaust leak will do it

Mine was doing that too. Found a cracked vac line going to the wastegate. Fixed that and I get a small amount of black smoke when I initially hit the accelerator but clears up quickly. Much better now.