This paper reports on a comprehensive, crank-angle transient, three dimensional, computational fluid dynamics (CFD) model of the complete lubrication system of a multi-cylinder engine using the CFD software Simerics-Sys / PumpLinx. This work represents an advance in system-level modeling of the engine lubrication system over the current state of the art of one-dimensional models. The model was applied to a 16 cylinder, reciprocating internal combustion engine lubrication system. The computational domain includes the positive displacement gear pump, the pressure regulation valve, bearings, piston pins, piston cooling jets, the oil cooler, the oil filter etc… The motion of the regulation valve was predicted by strongly coupling a rigorous force balance on the valve to the flow. The results show that the majority of the system pressure drop and flow rates occur in bearings, lifters and piston cooling jets, confirming the importance of a three-dimensional treatment for these components versus a relatively empirical zero or one-dimensional treatment. The newly developed CFD capability is timely because it can also drive the development of system-level models in adjacent design areas of topical interest such as engine oil warm up, interaction between lube oil and coolant temperatures, engine oil temperature distribution (which can impact oil life), uncovering of oil pick up tube, oil pump priming, bearing cavitation and dry spots, oil aeration, piston cooling jets, variable displacement vane pump and other related topics.