Metallic sonorous knocking during acceleration of the car speaks of detonation (explosion of a combustible mixture in the combustion chamber). Most likely, there is an ignition too early, you have flooded substandard gasoline or a large amount of carbon was formed in the combustion chamber. In addition, the cause of detonation can be engine overheating or old candles. The above sound is produced by the engine pistons taking over the shock wave from explosions of the fuel mixture in the combustion chambers. A long ride with this sound will destroy the engine. Therefore, it is better to immediately go to an electrician.