This paper describes the results of numerical simulations of a vehicle engine with dual mass flywheel coupled with dynamometer. The differential equations of the model are given. The mass moments of inertia and the torsional stiffness are taking into account. Numerical simulations are carried out. Natural frequencies of the system are determinate. Bode diagrams of the system are shown and analysed. Recommendations to reduce vibration by using an additional flexible coupling are given.