This paper presents a simulation model of an oil-lubrication gerotor pump for internal combustion engines. The model was constructed by using a monodimensional commercial code that accounted for all phenomena that occur during the revolution of the pump shaft. Several geometric considerations and theoretical observations are presented. An experiment was also performed to validate the simulation model. In these experimental tests, particular attention was paid to the behavior of the pressure oscillations during the pump shaft revolutions. The final aim of this activity is to obtain an instrument that allows the in-depth analysis of the functioning of the pump and lubrication circuit. Additionally, this instrument can be coupled with other models (e.g., variable valve actuation (VVA) and variable valve timing (VVT)) to account for different problems experienced by the hydraulic components of engines.