Sorry for the dump question, I am not a diesel mechanic by any means but learning about as fast as I can. I own an 89 Mack with an em6 motor and when I bought it the truck had very little blue smoke when you first started it up. In the last couple of months the truck appears to be blowing more blue smoke on start up than in the past. Truck runs fine and can't tell any difference in performance. I have been told that it could be many things but just looking for any options on what it could be.
Its like a gasser the valve guides wear they drip oil into the cylinders overnight and when you fire up in the morning she belches blue. If it doesn't clear up when the engine is hot then you have a engine that is getting tired. Heck look at the old Cummins 855 they belch blue like you wouldn't beleive they keep running. The old Ford 9000 I drove would belch blue so bad in the morning you couldn't see the truck which was blue in color :laugh The big problem is if you have emmissions cops out there checking on trucks that smoke too much then your going to need the truck fixed. White smoke is bad,blue smoke is okay black smoke means your making power How much oil does the truck burn in a day say you run the truck all day then the next morning you check the oil ?
What does white smoke mean then??
Head gasket leaking water in the motor.Cracked head.There are other reasons ,but these are the most common.
White smoke in the morning is okay white smoke when its hot is bad if its sweet smelling white smoke even worse
White smoke when the mtoor is warmed up means water in combustion chamber(head gasket, injector cups etc etc) White smoke when the mtor is cold is ok cause white smoke can mean unburnt fuel due to lack of heat(these diesels dont have spark plugs, they use compression and heat to ignite the fuel,a nd arent efficient when cold). Black smoke is unburnt fuel due to lack of air