What Causes the Zizzing Sound When Starting the Car?

[Georgia]

The zizzing sound after starting the car may be due to the following reasons: 1. Carbon deposits in the engine. Over time, old engine oil becomes thinner, leading to an accumulation of carbon deposits. When new oil is added, the engine may not adapt to the oil's viscosity immediately, potentially causing higher RPMs and increased engine noise. Solution: Regularly clean the car's intake system at a 4S shop to reduce carbon buildup. 2. The engine oil does not meet the standard or is overfilled. Excessive oil in the engine creates unnecessary resistance to the crankshaft's rotation, affecting power output and increasing fuel consumption. Solution: Change the engine oil regularly, maintain an appropriate oil level (slightly below the upper mark on the dipstick is ideal), and clean or replace the oil filter cartridge periodically.