Mitsubishi Eclipse engine vibration issue after long block replacement, potential harmonic balancer concern on Mitsubishi Eclipse

Some Mitsubishi Eclipse owners report experiencing engine vibration after a long block replacement, which may indicate potential issues with the harmonic balancer. Symptoms such as unusual vibrations, rattling or clunking noises, misfires, and an illuminated check engine light can suggest harmonic balancer failure. The harmonic balancer is crucial for absorbing engine vibrations, and if it becomes worn or fails, excessive engine shaking may occur. Owners are advised to diagnose the issue by checking if the vibration decreases when the vehicle is in neutral, which could also point to problems with the engine's motor mounts. It is essential to address any concerns regarding the harmonic balancer promptly to prevent further damage to the engine and its components. Engaging with Mitsubishi Eclipse forums can provide additional support and insights for those facing similar issues.