What does engine roar mean?

[McJeremiah]

Engine roar refers to abnormal noises produced when the engine malfunctions. The causes of abnormal noises in car engines include aging or loosening of engine mounts, piston slap, misfiring noises, excessively dirty throttle bodies, or excessive carbon buildup in fuel injectors. Aging or loosening of engine mounts: Engine mounts, also known as rubber mounts or engine brackets, are generally installed between the engine and the car body, connecting the body and the engine to secure the engine. Their most important function is to provide cushioning and vibration damping. Once the engine mounts age or become loose, the engine's vibrations will produce abnormal noises, and the mounts need to be replaced. Piston slap: Piston slap occurs when the piston tilts and the direction of lateral pressure changes, causing the contact surface between the piston and the cylinder to shift from the secondary thrust side to the main thrust side, resulting in lateral oscillation. Consequently, the engine periodically produces a knocking sound as the piston strikes the cylinder. This can be resolved by replacing the engine oil. Excessively dirty throttle body or excessive carbon buildup in fuel injectors: If the engine has severe carbon buildup, leading to idle vibrations, increased fuel consumption, and reduced power, it can cause abnormal engine noises. Cleaning the engine carbon deposits, washing the throttle body, and replacing the oil seals and spark plugs can resolve the issue. Misfiring noises: Engine misfiring mainly refers to one or more cylinders not functioning properly, typically manifested as noticeable intervals in the exhaust gas flow, severe shaking of the exhaust pipe, and clear "popping" or thumping sounds from the engine. This phenomenon is closely related to faults in the ignition coils, so the ignition coils need to be inspected and repaired.