Big Bart
Tow&Slow
Hard to say without questioning prior owner but some thoughts
1) As Nero suggested PO was not running diesel engine rated oil like Delo, Rotella, Delvac, Amsoil,etc. These are formulated with detergents to minimize that. Or waiting too long to change it.
2) Maybe the IP was turned way up to “roll coal” but was polluting the cylinders and gumming up the rings.
3) Maybe PO was running waste oil or home made bio fuel currently or in the past.
4) Maybe the engine sat for a long time and the rings got stuck. I have seen this on this site. Truck sat for years, now running, running a little rough or burning some oil. After a tank or two of good diesel, fresh oil, and some run time things free up.
5) Running too hot. Maybe prior owner did not have it timed, turned up fuel mixture on IP, or if turbocharged did not what his cylinder temps. Baked in oil, soot, and other contaminants from the diesel into the rings and grooves.
6) Maybe multiple of the above.
Again hard to say without knowing the history and being able ask questions about oil, oil change frequency, did they or the PO before them mess with the IP, did the truck smoke, did it sit for long periods of time, etc.
Good news is you will be putting in a new thermostat, fresh rings at a minimum, proper fresh oil, timing the IP, perhaps fresh injectors, fresh diesel, and that really leaves looking for smoke issues and watching your temps. But if rolling coal after the rebuild you will want to address that.
1) As Nero suggested PO was not running diesel engine rated oil like Delo, Rotella, Delvac, Amsoil,etc. These are formulated with detergents to minimize that. Or waiting too long to change it.
2) Maybe the IP was turned way up to “roll coal” but was polluting the cylinders and gumming up the rings.
3) Maybe PO was running waste oil or home made bio fuel currently or in the past.
4) Maybe the engine sat for a long time and the rings got stuck. I have seen this on this site. Truck sat for years, now running, running a little rough or burning some oil. After a tank or two of good diesel, fresh oil, and some run time things free up.
5) Running too hot. Maybe prior owner did not have it timed, turned up fuel mixture on IP, or if turbocharged did not what his cylinder temps. Baked in oil, soot, and other contaminants from the diesel into the rings and grooves.
6) Maybe multiple of the above.
Again hard to say without knowing the history and being able ask questions about oil, oil change frequency, did they or the PO before them mess with the IP, did the truck smoke, did it sit for long periods of time, etc.
Good news is you will be putting in a new thermostat, fresh rings at a minimum, proper fresh oil, timing the IP, perhaps fresh injectors, fresh diesel, and that really leaves looking for smoke issues and watching your temps. But if rolling coal after the rebuild you will want to address that.