To assist in the development of engine vibration isolation techniques for new transverse front wheel drive vehicles, simulations of engine and vehicle structural response were developed. A simulation of engine vibration response to engine imbalance forces and firing pulses is presented which provided mount forces as input to a vehicle structure simulation. Current design techniques using properties of engine rigid body motion are discussed. Simulation predictions of engine modal characteristics and response correlate well with laboratory measurements of engine motion and mount forces. These results show that connections other than engine mounts between engine and vehicle structure such as hoses, drivetrain, and exhaust system are important vibration transmission paths.