The piston pin, which acts as the connection between the piston and the connecting rod, is a crucial component in the internal combustion engine. It transfers the cylinder pressure of combustion to the crankshaft and is subjected to high stress and harsh lubrication conditions. Pin seizure is a severe problem in new engine development and coatings could be one of the solutions to this problem. However, by advancing the knowledge about the lubrication effect and the contact patterns on the pin’s surface, it is possible to find more cost-effective methods, such as modifying the profile or adding oil grooves. A numerical model was developed in this study to investigate the lubrication and dynamics of the piston pin, taking into account the deformation of the structures and oil cavitation. The model employs multi-body dynamics and elasto-hydrodynamic lubrication, and incorporats various boundary conditions, multigrade oil properties, the break-in process, and the influence of gun-drill holes. Simulation results from the model can be used to optimize the profiles and design parameters for the piston system, balancing trade-offs among friction, durability, and other performance factors.