Glend wrote:
Yep the oil is doing it job (keeping the soot is suspension). This is normal for a diesel, and has become more of an issue over the years with the introduction of Exhaust Gas Recirculation (EGR) on these engines. EGR, while having emissions benefits, does create problems for oils and the abrasive nature of the soot particles can wear your piston rings unless you keep relatively clean oil in the engine (in other words shorter interval oil changes than you could get away with in gas power vehicles). Mobil 1, while a great oil in terms of wear management and friction, is not very good at managing soot in diesel engines as it does not suspend soot like a diesel specific oil would. Mobil 1 is a CF rated oil, while the good diesel specific oils are generally using CI-4 and CJ category additive packages now. IMHO a CRD owner should make themselves familiar with the chemical additive packages of the various oils to insure long lived engines with optimal protection.
I may not know that much about diesel engines but the reason you have stated is why I choose Shell Rotella T. it is made for diesel trucks.