My buddy has a 2005 dodge 3500 cummins and here lately it has started blowing black smoke really bad and its bone stock no motor or exhaust modifications..he was asking me if something could be wrong with but i had no clue so im wanting to know if you guys know what it could be....It's got 103,000 miles on it as of now...

Bad or stuck injector

Thankss......

Tell him to fix asap. My buddy let one go too long and it looks like he ruined the motor :rolleyes:.

If air filter is clogged it will bellow black smoke! If he has done zero mods than it has to be one of two things way too much fuel or way too little air. I would start with the easy one first and see if something in the air intake is clogged. then work over toward the fuel side.
Wish you luck!

Thanks..we'll check the air filter tommorrow and hope thats alll it is...

Have you checked to see if it is throwing any codes? Key on (not full start) key off, on, off, on and leave it. If there are any stored codes they will read across the odometer. Look them up online or right them down and report back.

I saw him today and we checked out the filter and its in perfect condition and its not throwing any codes because we checked that to so I guess its the injectors...