cummins signature low oil pressure 10000km's after service.

You will probably find the oil pressure comes back to normal if you replace the oil filter. If it does, the oil filter is getting plugged up with carbon. If this is the case, something is very wrong with the engine. The carbon is getting into oil by getting past the piston rings from either failed, or failing injectors normally. There really is no test for this as the engine performance will be normal. The fuel spray pattern may be off and spraying fuel on the cylinder walls where it is partially burning and turning to carbon and packing up in the rings. This usually leads to an overhaul because once the rings are packed, that's it. They have to be taken out to be cleaned/replaced. With plugged up rings you will score the liners pretty quickly. What year and model is the engine? EGR and DPF engines are more prone to this with exceptionally dirty EGR systems. Plugged or failing sensors can lead to incorrect fuel timing and metering resulting overfueling and carbon build ups as well.

 

It might not apply to your engine, but some brand of oil filters used on Cummins will cause those symptoms. Might want to try different brand filters.

 

You need to have the static timing checked if the injector cam is not within a few thousands of the timing code it will cause excessive soot build up in the oil and will plug the oil filter causing low oil pressure this is common because the injector cam and valve cam are tapper fit with no woodruff key the timing wedges are only to get you close

 

Usually you will only log a fault if you are farther out of time. Example setting the lash on the idler gears to loose or not knowing how to set up the scissor gear. It doesn't take much to alter the timing just 4-5 thousands if I remember correctly

 

Your welcome hope it helps