have a John Deere 644k black smoke constantly coming out of exhaust either cold or hot, rough running. there was an egr code replaced the EGR that error is gone now but still smoking and running rough. replaced fuel and air filters as well. any direction from here? could it be injectors? thanks
I'll spit ball a bit, without knowing the EGR fault code or much about the machine at all that about all I can do. Who knows it could prove to be useful... It could be injectors but you could check a few cheaper things first. Inlet air could be restricted, or boost lost from a leak in the boosted air system (plugged cooler, cut boot, cracked aftercooler, blown o-ring. Pressurize the system - 25PSI would be max I would go and you would see the leak before then) Exhaust leaks before turbo causing low boost (visible leakage from manifold or turbo joint) Turbo function itself (wastegate stuck open not allowing boost to build, turbo is junk check for housing and wheel contact) If all those seem to check OK then you could look into the fuel system at that point. Good luck man.
Serial number? Codes?
2791.13 was the EGR code. replaced EGR, removed the cover as well and it wasn;t to bad inside. cleaned that up. still heavy smoke and idling rough
thanks checked that out and everything appears to be as it should be. will send it off to dealer thanks for the help