06 cummins... bought used.. had it 45 days, never smoked. Til other day.. 144k miles.. new injectors at 130k bosch brand (have reciept from shop) started to run stanadyne (lube formula) since april1st.. (day i bought it) starts, and idles fine.. power seems good. Great mpg 16.4 in town. Stock except for AFE intake and 5" exhaust and cummins exhaust brake.. hauled camper last weekend(8K) .. went great.. started to puff black at start up after that.. i used exhsust brake alot that weekend.. now "sometimes" it puffs white at cold start, then goes away..always has a little black at cold start.. almost no blow by when cold, and even less when warm.. coolant level is full, never changed.. keeping an eye on oil level to see if its burning it thru engine or leaking at turbo..also warching to make sure it dont rise from leaky injector.. cleaned air filter twice since i bought it just to be sure..
Im thinking..sticky injector, needs new fuel filter (which i ordered a 5 micron to change it out), scored piston wall or bad ring, valves out of adjustment, valve guide seal, leaking turbo??
I didnt run it hard pulling camper, so im sure my EGT's were good..
Am i on the right track? Im a diesel newbie..thx for reading, any info/advise is appreciated

 

Note* previous owner had it on synthetic oil, which i will continue.. not sure what brand..i will do that soon when i do fuel filter..

 

might have a small boost leak