Hello there. 2008 6.4 had a glow plug code come up, changed it code still came up. Pit in a new gpcm code code still came back now im going to put on new gp harnesses. With that being said after i put on the new gpcm i noticed smoke coming from my oil fill canister, the hose had come off and i reinstalled it but then i took off the fill cap while the engine was running and there is smoke coming out. Normally i associate that as an engine having blow by. Is this normal for a diesel or am i totally screwed and need a rebuild. Thanks in advance.