Engine producing black smoke

hey everyone I am taking the course, but I'm also a marine engineer on a ship, after working on one of our 4 stroke diesels (checking valve lash) a couple weeks later it started producing some black exhaust smoke. I checked all exhaust gas temps on each cylinder, and they seemed all with in normal operating range. Also checked exhaust temp before and after the turbo and that seemed fine. I then check the turbo its self which looked fine too (normal rpm, normal boost across the aftercooler, air filter was clean.) I went and rechecked the lash and it is all still in spec. I'm just curious if anyone has any other suggestions on what could possibly be causing the engine to smoke, also fuel pressure is with in normal operating parameters. I compared all readings from this diesel to another one and all reading with same load are the almost identical.

I assume you're talking about marine diesels, of some sort?

I would suspect a faulty - leaking or stuck - injector. Depending on the specifics of the engine installation, you may be able to shut down each injector in turn, to see if that helps narrow it down.

yes sorry not to clarify marine diesel generators, after searching for some time it was decided to just pull each injector and pop test them because we can not isolate individual injectors. I'll update with findings but currently I was just watch every now and then cylinder 7 gives high EGTs then returns back to normal.

So issue was a small leak in injector nozzle, seems like it wasn't enough to increase EGTs beyond standard operating, but enough to produce more black smoke then normal. I replaced the nozzle and reset the pressure and exhaust gases are much cleaner looking, and EGT on that cylinder actually went down! Thank god for these classes because it defiantly helped the trouble shooting.

Good stuff Ryan, thank you so much for following up on your post. Glad you got it ironed out.

Nick