Why is the engine noise loud when driving?

[DiValeria]

When driving, the reasons for loud engine noise are: 1. Carbon deposits in the cylinders, throttle, spark plugs, and intake; 2. The use of incompatible fuel grades in the fuel system, leading to reduced vehicle power output and performance; 3. The air filter is not cleaned in time, causing blockage and insufficient air volume, resulting in an overly rich combustible mixture; 4. Insufficient engine oil, insufficient engine coolant, or malfunctioning engine cooling system. The solutions for loud engine noise when driving are: 1. Install some high-quality sound-absorbing foam materials under the engine hood to suppress vibrations caused by the hood; 2. Inspect or replace the intake and exhaust pipes; 3. Use insulated pistons to increase the temperature of the combustion chamber walls, shorten the ignition delay period, and reduce the combustion noise of direct-injection diesel engines with space atomization combustion systems.